Guidelines Establishing Test Procedures for the Analysis of Pollutants; Available Cyanide

SUMMARY: This proposed regulation would amend the Guidelines

Establishing Test Procedures for the Analysis of Pollutants under

Section 304(h) of the Clean Water Act by adding Method OIA-1677:

Available Cyanide by Flow Injection, Ligand Exchange, and Amperometry.

Method OIA-1677 employs flow injection analysis (FIA) to measure

``available cyanide.'' Method OIA-1677 is being proposed as an

additional test procedure for measuring the same cyanide species as are

measured by currently approved methods for cyanide amenable to

chlorination (CATC). In some matrices, CATC methods are subject to

significant test interferences. In contrast, Method OIA-1677

demonstrates greater specificity for cyanide for matrices in which

interferences have been encountered using CATC methods. In addition,

Method OIA-1677 measures cyanide at lower concentrations and offers

improved precision and accuracy over currently approved CATC methods.

Method OIA-1677 also offers improved laboratory safety and reduces

laboratory waste compared to currently approved CATC methods. This

significantly reduces the generation of hazardous waste by the

laboratory. Cyanide analysis by Method OIA-1677 is also more rapid than

by currently approved methods.

DATES: Comments on this proposal must be submitted on or before

September 8, 1998.

ADDRESSES: Send written comments on the proposed rule to ``Method OIA-

1677'' Comment Clerk (Docket #W-98-08); Water Docket (4101);

Environmental Protection Agency; 401 M Street, SW., Washington, DC

20460. Commenters are requested to submit any references cited in their

comments. Commenters are also requested to submit an original and 3

copies of their written comments and enclosures. Commenters that want

receipt of their comments acknowledged should include a self addressed,

stamped envelope. All comments must be postmarked or delivered by hand.

No facsimiles (faxes) will be accepted.

Data available: A copy of the supporting documents cited in this

proposal is available for review at EPA's Water Docket; 401 M Street,

SW, East Tower Basement, Washington, DC 20460. For access to docket

materials, call (202) 260-3027 between 9 a.m. and 3:30 p.m. for an

appointment. An electronic version of Method OIA-1677 will be available

via the Internet at http://www.epa.gov/OST/Tools.

FOR FURTHER INFORMATION CONTACT: Dr. Maria Gomez-Taylor, Engineering

and Analysis Division (4303), USEPA Office of Science and Technology,

401 M Street, SW, Washington, DC 20460, or call (202) 260-1639.

SUPPLEMENTARY INFORMATION:

Potentially Affected Entities

EPA Regions, as well as States, Territories and Tribes authorized

to implement the National Pollutant Discharge Elimination System

(NPDES) program, issue permits that comply with the technology-based

and water quality-based requirements of the Clean Water Act. In doing

so, the NPDES permitting authority, including authorized States,

Territories, and Tribes, make a number of discretionary choices

associated with permit writing, including the selection of pollutants

to be measured and, in many cases, limited in permits. If EPA has

``approved'' standardized testing procedures (i.e., promulgated through

rulemaking) for a given pollutant, the NPDES permit must include one of

the approved testing procedures or an approved alternate test

procedure. Therefore, entities with NPDES permits could be affected by

the standardization of testing procedures in this rulemaking. These

entities may be affected because NPDES permits may incorporate one of

the standardized testing procedures in today's rulemaking. In addition,

when a State, Territory, or authorized Tribe provides certification of

federal licenses under Clean Water Act section 401, States, Territories

and Tribes are directed to use the standardized testing procedures.

Categories and entities that may ultimately be affected include:

------------------------------------------------------------------------

Examples of potentially

Category affected entities

------------------------------------------------------------------------

State and Territorial Governments and States, Territories, and Tribes

Indian Tribes. authorized to administer the

NPDES permitting program;

States, Territories, and

Tribes providing certification

under Clean Water Act section

401; Governmental NPDES

permittees.

Industry............................... Industrial NPDES permittees.

Municipalities......................... Publicly-owned treatment works

with NPDES permits.

------------------------------------------------------------------------

This table is not intended to be exhaustive, but rather provides a

guide for readers regarding entities likely to be affected by this

action. This table lists the types of entities that EPA is now aware

could potentially be affected by this action. Other types of entities

not listed in the table could also be affected. If you have questions

regarding the applicability of this action to a particular entity,

consult the person listed in the preceding FOR FURTHER INFORMATION

CONTACT section.

I. Authority

Today's proposal is pursuant to the authority of sections 301,

304(h), and 501(a) of the Clean Water Act (CWA), 33 U.S.C. 1314(h),

1361(a) (the ``Act''). Section 301 of the Act prohibits the discharge

of any pollutant into navigable waters unless the discharge complies

with a National Pollutant Discharge Elimination System (NPDES) permit,

issued under section 402 of the Act. Section 304(h) of the Act requires

the Administrator of the EPA to ``promulgate guidelines establishing

test procedures for the analysis of pollutants that shall include the

factors which must be provided in any certification pursuant to section

401 of this Act or permit applications pursuant to section 402 of this

Act.'' Section 501(a) of the Act authorizes the Administrator to

``prescribe such regulations as are necessary to carry out his function

under this Act.'' The Administrator also has made these test procedures

applicable to monitoring and reporting of NPDES permits (40 CFR part

122, Sec. 122.21, 122.41, 122.44, and 123.25), and implementation of

the pretreatment standards issued under section 307 of the Act (40 CFR

part 403, Secs. 403.10 and 402.12).

[[Page 36811]]

II. Background

A. Cyanide

Cyanides are, as a class, one of the toxic pollutants pursuant to

section 307(a)(1) of CWA (see the list of toxic pollutants at 40 CFR

401.15). Total cyanide is a priority pollutant as derived from the

toxic pollutant list (see 40 CFR Part 423, Appendix A).

In the context of analytical methods, cyanide or cyanides refers to

the group of simple and complex chemical compounds that can be

determined as cyanide ion (CN-). Cyanides are of the form

A(CN)X, where A is an alkali such as sodium or potassium, or

a metal such as calcium, and x is the number of CN groups attached to

A. Cyanides are present in aqueous solutions as CN- and as

hydrocyanic acid (HCN or hydrogen cyanide). The proportion of

CN- and HCN in solution is dependent on the pH and the

dissociation constant for HCN. At low pH, the cyanide exits as HCN; at

high pH, it exists as CN-. At the near-neutral or slightly

acidic pH of most natural waters, nearly all cyanide is present as HCN.

Most of the metal cyanides are insoluble or only slightly soluble in

water but may form a variety of soluble cyanide complexes when a

cyanide such as potassium or sodium cyanide is present.

Hydrogen cyanide is the cyanide species most toxic to aquatic life.

The toxicity of the other cyanides is attributable to the degree of

their dissociation and conversion to HCN. Some cyano-metal complexes,

such as those of zinc and cadmium, dissociate almost totally (i.e., a

knowledge of the complex can be used to determine the amount of

cyanide). Other cyano-metal complexes, such as those of iron,

dissociate little. For these complexes, a large amount can be present

without cyanide being detected. Still, other complexes, such as

mercury, nickel, and silver, dissociate partially and only under

certain conditions. For complexes that release some, but not all, of

the cyanide ion, the amount of dissociation must be known to determine

the amount of cyanide. This total, partial, or near lack of

dissociation presents a difficulty in the determination of cyanides, as

explained below.

B. Need for Improved Methods for Cyanide

Methods proposed in Guidelines Establishing Test Procedures for the

Analysis of Pollutants under section 304(h) of the Clean Water Act are

listed at Title 40 of the Code of Federal Regulations, Sec. 136.3. EPA

had received numerous letters and comments regarding interference

problems when the currently approved methods were used to test certain

sample matrices and was therefore aware of the need for a cyanide

method that reduced or eliminated these interferences. A method for

measuring available cyanide by flow injection analysis (FIA) had been

developed by ALPKEM in cooperation with the University of Nevada at

Reno, Mackay School of Mines in 1995. Besides overcoming most matrix

effect problems, Method OIA-1677 uses amperometry as an innovative

technology to improve the detection of available cyanide. Method OIA-

1677 is faster, more accurate and precise, and allows determination of

available cyanide at lower concentrations than currently approved

methods. Method OIA-1677 is also safer because it requires a smaller

amount of a potentially hazardous sample, requires less manual

operations where accidents could lead to exposure, and uses less

hazardous substances in the sample preparation and determinative steps.

C. Methods for Determination of Cyanide

Methods presently approved at 40 CFR Part 136 measure cyanide in

two ways: as ``total cyanide'' and ``cyanide amenable to chlorination''

(CATC). A third way is as ``weak-acid dissociable'' (WAD) cyanide but

there is presently no approved method for WAD cyanide in 40 CFR Part

136. Methods for determination of total cyanide attempt to measure all

cyanide species that may dissociate in the environment over time and

when exposed to natural forces (e.g., heat, light, water of varying

hardness, pH) but ultimately fail to do so because many species cannot

be dissociated completely under normal laboratory conditions. The CATC

and WAD methods, and Method OIA-1677, which employs ligand exchange,

all attempt to measure ``available'' cyanide, i.e., cyanide species

that dissociate in the presence of chlorine and/or acid. The species of

cyanide measured by these methods are cyanide ion (CN-),

hydrogen cyanide (HCN), and the cyano-complexes of zinc, copper,

cadmium, mercury, nickel, and silver. The net result is that the WAD,

CATC, and OIA-1677 methods all measure nearly the same species of

cyanide. The term ``available cyanide'' is used in Method OIA-1677

because the chlorination reaction used in the CATC methods is not

employed, although the cyanides determined are the same.

Methods for total cyanide employ reflux distillation in the

presence of sulfuric acid and magnesium chloride to dissociate

CN- from cyanide-metal complexes. This process is more

vigorous than the dissociation processes used in the WAD, CATC, and

ligand-exchange methods, and a greater number of cyanide species are

dissociated in the distillation process. The HCN liberated during the

distillation is captured in an aqueous solution of sodium hydroxide and

the cyanide in the solution is determined spectrophotometrically or

titrimetrically.

Cyanide amenable to chlorination (CATC) is determined by

chlorinating the available cyanide in the sample using calcium

hypochlorite (Ca(OCl)2), measuring the HCN using the total

procedure, and finding the CATC concentration by difference between the

total cyanide measured before and after the chlorination.

Available cyanide is determined in Method OIA-1677 by flow

injection, ligand exchange, and amperometric detection. The ligand-

exchange reagents displace cyanide from cyano-metal complexes. Further

details of Method OIA-1677 are given in a description of the method

below.

As stated above, no method measures all species of cyanides because

several species (such as cobalt and gold cyanides) are so stable that

they are either not dissociated or are only slightly dissociated in the

reflux distillation or chlorination processes. Method OIA-1677 and CATC

methods measure easily dissociable and partially dissociable species.

Most notable among the partially dissociable species are the certain

cyanides of nickel, mercury, and silver when these cyanides are present

at high concentrations (ca 2 mg/L). These cyanides are recovered in the

range of 55--85 percent in the CATC methods. In contrast, these species

are recovered completely in Method OIA-1677, and this is the

significant difference between the performance of Method OIA-1677 and

approved methods for CATC. As a result, if a sample contains high

concentrations of certain cyanides of nickel, mercury, or silver, the

result will be somewhat higher when Method OIA-1677 is used, provided

no interferences are present. At concentrations below approximately 0.2

mg/L, the recoveries of these cyanides from CATC methods and Method

OIA-1677 are all approximately equivalent and near 100 percent.

D. Effect of Interferences on Cyanide Methods

The CATC determination is highly susceptible to interferences, as

many substances other than cyanides can react in the chlorination

process. For an overview of the nature and magnitude of these

interferences, see the paper

[[Page 36812]]

presented by Goldberg, et. al. at the Seventeenth Annual EPA Conference

on Analysis of Pollutants in the Environment, May 3-5, 1994 (available

from the EPA Sample Control Center, 300 N. Lee Street, Alexandria, VA

22314 (703-519-1140). Interferences in the CATC determination may be by

thiocyanate (SCN-), sulfide (S2-), carbonates

(HCO3-, CO32-), nitrite

(NO2-), oxidants (ClO4-,

O3, H2O2), bisulfite

(HSO3-), formaldehyde (HCHO), surfactants, and

metals. Method OIA-1677 is either not susceptible to these

interferences or contains procedures that eliminate these interferences

or mitigate their effects. The reason that this method is much less

susceptible to interferences than the approved CATC methods is that the

chlorination reaction is not employed. Rather, the aqueous sample

passes a gas diffusion membrane through which the HCN diffuses, as

explained in greater detail in the later section of this preamble that

describes Method OIA-1677. With approval of Method OIA-1677, EPA

believes that most of the reported interference problems in the

determination of cyanide would be overcome.

Interferences in the CATC methods normally produce an inflated

result for cyanide and, in many instances, the measured level exceeds

the concentration for total cyanide, potentially providing a more

controversial result in some regulatory contexts. Because Method OIA-

1677 is nearly immune to the interferences that inflate results from

CATC methods, the result of an analysis using Method OIA-1677 will

nearly always be lower, and therefore closer to the true value for

cyanide than a result from an analysis using a CATC method. The only

exception may be for an analysis in which interferences are not present

but certain cyanides of nickel, mercury, or silver are present at high

concentrations, as described above. Therefore, the tradeoff in use of

Method OIA-1677 versus presently approved CATC methods is that, with

Method OIA-1677, there is a reduced susceptibility to interferences,

whereas with approved CATC methods, there is a somewhat decreased

result if certain cyanides of nickel, mercury, or silver are present at

high concentrations. EPA believes that the tradeoff heavily favors use

of Method OIA-1677 based on the expected susceptibility of CATC methods

to interferences combined with the small probability that a cyanide of

nickel, mercury, and silver will be present at a high concentration and

be the dominant cyanide in a given discharge. Dominance is important

because if a cyanide of nickel, mercury, or silver is present at a

concentration that is small in comparison to another cyanide present,

the effect on the measured cyanide concentration will be diminished in

proportion to the concentration relative to the other cyanide.

Because the lowest result for a given cyanide determination can be

produced by either Method OIA-1677 or by a presently approved CATC

method, dischargers will likely choose the method that produces the

lowest result. The adverse environmental impact to choosing presently

approved CATC methods is that not all of the nickel, mercury, or silver

cyanide will be recovered (and measured), if any of these cyanides are

present.

E. Regulatory Effects of Use of Different Methods

A regulatory problem may occur when a sample of a given discharge

is split and a discharger chooses Method OIA-1677 and a regulatory

authority chooses an approved CATC method (or vice versa) and one

result shows a violation of a permit limit and the other does not. EPA

believes that the difference can be worked out in technical discussions

between the discharger and the regulatory authority based on the data

produced. If these data show that an interference was present, Method

OIA-1677 will likely produce the lower result and this result should be

relied upon. On the other hand, if the discharger knows that nickel,

mercury or silver cyanide is present in the discharge in high

concentration and is dominant, the result from the CATC method would be

appropriate because it is most consistent with the method used for

permit development. Further, it is unlikely that a discharger would

select Method OIA-1677 if it knew that a cyanide of nickel, mercury, or

silver was present at high concentration, unless interferences were so

large that they overwhelmed the effect of the greater recovery. The

concern would then be that the regulatory authority employed Method

OIA-1677, not knowing that a cyanide of nickel, mercury, or silver was

present at a high concentration and dominant in the discharge. However,

the discharger could inform the regulatory authority of this presence

and may rely upon the text in this preamble and in the technical

literature to convince the regulatory authority that the violation is a

result of the regulatory authority's use of Method OIA-1677. Finally,

EPA believes that occurrences of this problem will be rare and it is

more likely that use of Method OIA-1677 will produce a lower result

because it is nearly interference free.

F. Analysis Time

The reflux distillation procedure required by CATC methods,

including setup and measurement, takes approximately two hours to

perform. Therefore, determination of CATC takes approximately four

hours of analysis time. In contrast, Method OIA-1677 takes

approximately two minutes to perform. This difference will be

especially significant for laboratories performing many CATC analyses.

III. Summary of Proposed Rule

A. Introduction

This proposed rule would make available at part 136 an additional

test procedure for measurement of available cyanide. Currently approved

methods for measurement of available cyanide are based on sample

chlorination. Method OIA-1677 as proposed today uses a flow injection/

ligand exchange technique to measure available cyanide. Although Method

OIA-1677 and chlorination methods both measure available cyanide, it is

possible that the results produced by the two techniques will vary

slightly, as detailed above. EPA offers Method OIA-1677 as another

testing procedure for a variety of purposes including: permit

applications and compliance monitoring under the National Pollutant

Discharge Elimination System (NPDES) under CWA Section 402; ambient

water quality monitoring; CWA Section 401 certifications; development

of new effluent limitations guidelines, pretreatment standards, and new

source performance standards in EPA's water programs; and for general

laboratory use. This rulemaking does not propose to repeal any of the

currently approved methods that test for available cyanide. For NPDES

permits, the permitting authority should decide which method is

appropriate for the specific NPDES permit based on the circumstances of

the particular effluent measured. If the permitting authority does not

specify the method to be used for the determination of available

cyanide, a discharger would be able to use Method OIA-1677 or any of

the presently approved CATC methods.

B. Summary of Proposed Method OIA-1677

Method OIA-1677 is divided into two parts: sample pretreatment and

cyanide quantification via amperometric detection. In the sample

pretreatment step, ligand-exchange reagents are

[[Page 36813]]

added to a 100-mL sample. The ligand-exchange reagents displace cyanide

ions (CN-) from weak and intermediate strength metallo-

cyanide complexes.

In the flow-injection analysis system, a 200-L aliquot of

the pretreated sample is injected into the flow injection manifold. The

addition of hydrochloric acid converts cyanide ion to hydrogen cyanide

(HCN). The hydrogen cyanide diffuses through a membrane into an

alkaline receiving solution where it is converted back to cyanide ion

(CN-). The amount of cyanide ion in the alkaline receiving

solution is measured amperometrically with a silver working electrode,

silver/silver chloride reference electrode, and platinum counter

electrode at an applied potential of zero volt. The current generated

in the cell is proportional to the concentration of cyanide in the

original sample, as determined by calibration.

C. Comparison of Method OIA-1677 to Current Methods

Methods currently approved for determination of available cyanide

all test for CATC. Although they represent the best methods available

to date, these methods are prone to matrix interference problems. EPA

considers Method OIA-1677 to be a significant addition to the suite of

analytical testing procedures for available cyanide because it (1) has

greater specificity for cyanide in matrices where interferences have

been encountered using currently approved methods, (2) has improved

precision and accuracy compared to currently approved CATC cyanide

methods, (3) measures available cyanide at lower concentrations, (4)

offers improved analyst safety, (5) shortens sample analysis time, and

(6) reduces laboratory waste.

Method OIA-1677 is not subject to interferences from organic

species. The flow-injection technique of Method OIA-1677 excludes all

interferences, except sulfide. Sulfide is eliminated by treating the

sample with lead carbonate and removing the insoluble lead sulfide by

filtration prior to introduction of the sample to the amperometric cell

used for cyanide detection.

Method OIA-1677 was tested against two existing cyanide methods:

Method 335.1, an EPA-approved CATC method, and Standard Method (SM)

4500 CN- I, a weak-acid dissociable (WAD) cyanide method.

Comparative recovery and precision data were generated from simple

metallo-cyanide species in reagent water. Recovery and precision of

each method was comparable for the easily dissociable cyanide species.

Method OIA-1677 showed superior precision and recoveries of mercury

cyanide complexes.

While Method 335.1 does not specify a method detection limit,

colorimetric detection is ``sensitive'' to approximately 5 g/

L. The method detection limit (MDL; described at 40 CFR part 136,

Appendix B) is 0.5 g/L for Method OIA-1677, as determined in a

multi-laboratory study.

Method OIA-1677 offers improved analyst safety for two reasons. The

first reason centers on the generation of hydrogen cyanide gas, a

highly toxic compound. Although the proposed flow-injection analysis

(FIA) method and currently approved CATC methods all generate HCN, the

currently approved methods generate a larger quantity of gas during

distillation in an open distillation system. As such, extra care must

be taken to prevent accidental release of HCN into the laboratory

atmosphere. Method OIA-1677, because it tests a much smaller sample,

generates significantly less HCN. In addition, the gas is contained in

a closed system with little possibility for release. The second reason

for improved safety centers on the use of hazardous substances.

Currently approved CATC methods require use of hazardous substances in

the distillation and color developing processes. These hazardous

substances include hydrochloric acid, pyridine, barbituric acid,

chloramine-T, and pyrazolone. Method OIA-1677 requires only

hydrochloric acid at a much lower concentration than is used in CATC

procedures.

Method OIA-1677 offers a reduced analysis time which should

increase sample throughput in the laboratory. Method OIA-1677 uses an

automated mixing of the sample with hydrochloric acid and exposure to

the gas diffusion membrane in order for the sample concentration to be

determined. This process takes approximately two minutes per sample. As

a comparison, Method 335.1 requires a one-hour distillation procedure

plus the time necessary to add and develop the sample color to

determine the presence of cyanide.

Less laboratory waste is generated in Method 1667 because it

requires a much smaller sample size for testing. Method 335.1 requires

handling a sample size of 500 mL for distillation. Method OIA-1677

requires the addition of the ligand exchange reagents to 100 mL of

sample, from which 40-250 L is used for analysis. This reduces

the amount of both hazardous sample and toxic reagents that must be

handled and subsequently disposed.

D. Quality Control

The quality control (QC) in Method OIA-1677 is more extensive than

the QC in currently approved methods for CATC. Method OIA-1677 contains

all of the standardized QC tests proposed in EPA's streamlining

initiative (62 FR 14976) and used in the 40 CFR part 136, Appendix A

methods. An initial demonstration of laboratory capability is required

and consists of: (1) An MDL study to demonstrate that the laboratory is

able to achieve the MDL and minimum level of quantification (ML)

specified in Method OIA-1677; and (2) an initial precision and recovery

(IPR) test, consisting of the analysis of four reagent water samples

spiked with the reference standard, to demonstrate the laboratory's

ability to generate acceptable precision and recovery. An important

component of these and other QC tests required in Method OIA-1677 is

the use of mercuric cyanide (Hg(CN)2) as the reference

standard for spiking. Mercuric cyanide was chosen because it is fully

recovered in Method OIA-1677 and weak-acid dissociable (WAD) methods,

whereas mercuric cyanide is only partially recovered in the CATC

method. Therefore, mercuric cyanide demonstrates the ability of the

ligand-exchange reagents to liberate cyanide from moderately strong

metal-cyano complexes. Method OIA-1677 requires the use of standards of

known composition and purity, which facilitates more accurate

determination of recovery and precision and minimizes variability that

may be introduced from spiking substances of unknown or indeterminate

purity.

Ongoing QC consists of the following tests that would need to

accompany each analytical batch, i.e., a set of 10 samples or less

pretreated at the same time:

Verification of calibration of the flow injection

analysis/amperometric detection system, to verify that instrument

response has not deviated significantly from that obtained during

calibration.

Analysis of a matrix spike (MS) and matrix spike duplicate

(MSD) to demonstrate method accuracy and precision and to monitor

matrix interferences. Hg(CN)2 is the reference standard used

for spiking.

Analysis of a laboratory blank to demonstrate freedom from

contamination.

Analysis of a laboratory control sample to demonstrate

that the method remains under control.

Method OIA-1677 contains QC acceptance criteria for all QC tests.

Compliance with these criteria allows a

[[Page 36814]]

data user to evaluate the quality of the results. This increases the

reliability of results and provides a means for laboratories and data

users to monitor analytical performance, thereby providing a basis for

sound, defensible data.

E. Performance-based Measurement System

On October 6, 1997, EPA published a Notice of the Agency's intent

to implement a Performance Based Measurement System (PBMS) in all of

its programs to the extent feasible (62 FR 52098). The Agency is

currently determining the specific steps necessary to implement PBMS in

its programs and preparing an implementation plan. Final decisions have

not yet been made concerning the implementation of PBMS in water

programs. However, EPA is currently evaluating what relevant

performance characteristics should be specified for monitoring methods

used in the water programs under a PBMS approach to ensure adequate

data quality. EPA would then specify performance requirements in its

regulations to ensure that any method used for determination of a

regulated analyte is at least equivalent to the performance achieved by

other currently approved methods. Our expectation is that EPA will

publish its PBMS implementation strategy for water programs in the

Federal Register by the end of calendar year 1998.

Under PBMS, the analyst would have flexibility to modify Method

OIA-1677 or to use another method for the determination of available

cyanide provided the analyst demonstrates that the performance achieved

is at least equivalent to the approved method(s). Since inter-

laboratory performance data exists for Method OIA-1677, EPA is

proposing that these data be used to specify what performance

characteristics would be required for measurement of available cyanide

under PBMS. EPA is considering the following performance requirements

for the use of modified or alternative methods for the measurement of

available cyanide: (1) it measures the same cyanide species; (2) it

achieves an MDL that is equal or less than the MDL in Method OIA-1677,

or one-third the regulatory compliance level, whichever is greater; and

(3) it meets all the performance criteria specified in Table 1 of

Method OIA-1677 (initial precision and recovery, on-going precision and

recovery, calibration verification, and matrix spike/matrix spike

duplicate). The process for demonstrating acceptable performance is

specified in Section 9 of the method.

Once EPA has made its final determinations regarding implementation

of PBMS in programs under the Clean Water Act, EPA would incorporate

specific provisions of PBMS into its regulations, which may include

specification of the performance characteristics for measurement of

available cyanide and for other regulated pollutants in the water

program regulations.

EPA requests public comments on whether the performance

characteristics identified above (see Method OIA-1677 for performance

criteria) would be relevant performance characteristics under PBMS, and

whether there are other performance requirements that the Agency should

consider under PBMS for the measurement of available cyanide.

IV. Validation of the Method OIA-1677

ALPKEM developed the version of Method OIA-1677 proposed today

according to procedures set forth in EPA's Guide to Method Flexibility

and Approval of EPA Water Methods (EPA-821-D-96-004, December 1996)

which is available from the EPA's Water Resource Center (phone: 202-

260-7786). The version of Method OIA-1677 proposed today responds to

comments from users of earlier versions, results of the intra- and

interlaboratory studies, as well as results from several single-

laboratory MDL studies.

A. Intralaboratory Validation Study Results

Prior to interlaboratory testing, ALPKEM conducted a single-

laboratory validation study both to refine the method and to

demonstrate the method's specificity and selectivity. Those study

results, described briefly here, are detailed in the Report of the

Draft Method OIA-1677 Single Laboratory Validation Study that is

included in the docket for this proposed rule.

The single-laboratory study consisted of three sets of tests to

establish (1) the ability of Method OIA-1677 to identify the various

species of ``free'' metallo-cyanide complexes, (2) the ability of

Method OIA-1677 to identify cyanide in the presence of interferences,

and (3) the recovery and precision of Method OIA-1677 compared to EPA

Method 335.1 and SM 4500 CN-I. To determine Method OIA-1677's

identification of ``free'' metallo-cyanide complexes, two different

concentrations of 11 different metallo-cyanide complexes were each

analyzed individually in triplicate, for a total of 66 analyses. Method

OIA-1677 yielded recoveries ranging from 97 to 104 percent for six of

the eleven complexes (cadmium, copper, mercury, nickel, silver, and

zinc). However, as with the currently approved methods for available

cyanide, Method OIA-1677 did not determine cyanide in iron, gold, and

cobalt cyanide complexes.

To test the ability of Method OIA-1677's to identify cyanide in the

presence of other species, two different concentrations of 11

interferents were analyzed in triplicate for a single cyanide test

solution, resulting in a second set of 66 analyses. Even in the

presence of these interferents, cyanide recoveries ranged from 99 to

103 percent.

To compare the performance of Method OIA-1677 to the performance of

approved methods, 2 different concentrations of the same 11 ``free''

metallo-cyanide complexes given above were analyzed individually in

triplicate by the EPA-approved CATC Method 335.1, SM 4500 CN-I, and

Method OIA-1677. This resulted in a third set of 66 data points. These

results show improved recoveries and reduced relative standard

deviations for Method OIA-1677 compared to both the SM 4500 CN-I and

the CATC methods for selected analytes. For the mercury cyanide

complexes, recovery improved from 59 percent for SM 4500 CN-I to 99

percent for Method OIA-1677. High levels of interferences in the nickel

and silver determinations showed similar improvements over the CATC

method. However, data for zinc, cadmium, copper were comparable among

the three cyanide procedures. There was no recovery and thus no method

improvement for cobalt, gold, or iron cyanide complexes.

B. Interlaboratory Validation Study Results

In association with the Analytical Methods Staff (AMS) in EPA's

Office of Water, ALPKEM conducted an interlaboratory validation study.

Those study results, briefly described here, are detailed in a report

titled, The Interlaboratory Validation of Method OIA-1677, and are

included in the docket for this proposed rule.

The purpose of the interlaboratory study was (1) to confirm the

performance of Method OIA-1677 in multiple laboratories, (2) to assess

Method OIA-1677 interlaboratory data variability, and (3) to develop

Method OIA-1677 QC acceptance criteria.

Nine laboratories participated in the interlaboratory method

validation study, working cooperatively as the WAD Cyanide Round Robin

Group. Each laboratory analyzed an identical set of nine field samples

using Method OIA-1677. These field samples were

[[Page 36815]]

collected from nine different effluents ranging from a publicly owned

treatment works (POTW) to an industry likely to contain cyanide in its

effluent. Each sample was analyzed in triplicate using the FIA

procedure for a total of 243 analyses (9 laboratories x 9 samples in

triplicate).

Along with the analysis of the field samples, each laboratory

performed all required QC analyses, including initial calibration,

calibration verification, determination of initial precision and

recovery, blank analysis, determination of ongoing precision and

recovery (OPR), determination of matrix spike recovery and matrix spike

duplicate recovery (MS/MSD) in each sample type, assessment of recovery

of cyanide as Hg(CN)2 spiked into samples (ligand-exchange

reagent performance check or LERPC). In addition, each laboratory

performed an MDL study.

The relative standard deviation (RSD) of results across all

laboratories and all samples was 12 percent. The mean sample recoveries

across all effluent types tested was 96 percent, and the MS and MSD

mean recoveries were 99 percent across all effluent types tested. These

results exceed generally accepted norms for analytical chemistry

results.

Prior to collection of interlaboratory data, one study participant

submitted comments that focused on the difficulty in addition of the

proper amounts of WAD A & WAD B ligand-exchange reagents to a sample.

The difficulty occurred because of the variability of drop size. The

method was modified to designate a specific volume of ligand-exchange

reagent rather than a certain number of drops. The modified method was

distributed to interlaboratory study participants prior to testing.

C. Development of Quality Control Acceptance Criteria

Data from the interlaboratory study were used to develop QC

acceptance criteria for Method OIA-1677. Laboratory procedures and QC

calculations are fully described in the interlaboratory study report.

Criteria were developed for initial precision and recovery (IPR),

ongoing precision and recovery (OPR), and recovery of cyanide as

Hg(CN)2 spiked into reagent water samples (ligand-exchange

reagent performance check, LERPC). QC acceptance criteria for the IPR,

OPR, matrix spike (MS), matrix spike duplicate (MSD), and relative

percent difference (RPD) for the MS and MSD were calculated using

procedures described in EPA's Streamlining Guide. In addition to those

procedures, QC acceptance criteria also were developed for

Hg(CN)2 at the upper level of the analytical range. Criteria

for this LERPC test were developed according to the same procedure as

for the IPR test.

D. Method Detection Limit Studies

Nine single-laboratory MDL studies were performed as part of the

effort to determine MDLs and minimum levels (MLs). The MDL is defined

as the minimum concentration of a substance that can be measured and

reported with 99 percent confidence that the analyte concentration is

greater than zero. To determine the MDL, the laboratories were required

to follow the procedure in Appendix B to 40 CFR part 136.

In the Appendix B procedure, seven aliquots of reagent water are

spiked with the analyte or analytes of interest and analyzed by the

proposed method. For the MDL studies, KCN was used as the spiking

material. Spike levels were in the range of one to five times the

estimated detection limit. Following addition of KCN, cyanide levels in

each of the seven aliquots was determined. The MDL was determined to be

0.5 g/L CN-.

The minimum level of quantitation (ML) is defined as the level at

which the entire analytical system produces a recognizable signal and

an acceptable calibration point. The ML is determined by multiplying

the MDL by 3.18 and rounding the resulting value to the number nearest

to (1, 2, or 5) x 10n, where n is an integer. The ML for

Method OIA-1677 was calculated to be 1.0 g/L CN-.

However, because this calculated value was below the lowest calibration

standard used in the MDL study, the ML was set at the level of that

standard, 2.0 g/L CN-. Results of the MDL studies,

along with the relevant calculations, are detailed in the

interlaboratory study report.

V. Status of Currently Approved Methods

This action proposes to make Method OIA-1677 available for

measurement of available cyanide. The previously approved methods for

analysis of available cyanide, EPA Method 335.1, SM 4500-CN G, and ASTM

D2036-91(B), would not be withdrawn or otherwise affected by this

regulation. EPA specifically invites comment on this aspect of the

proposal, including the possible consequences and solutions if EPA were

to withdraw any such methods.

VI. Regulatory Requirements

A. Executive Order 12866

Under Executive Order 12866, (58 FR 51735 (October 4, 1993)) the

Agency must determine whether a regulatory action is ``significant''

and therefore subject to OMB review and the requirements of the

Executive Order. The Order defines ``significant regulatory action'' as

one that is likely to result in a rule that may: (1) have an annual

effect on the economy of $100 million or more or adversely affect in a

material way the economy, a sector of the economy, productivity,

competition, jobs, the environment, public health or safety, or State,

local, or tribal governments or communities; (2) create a serious

inconsistency or otherwise interfere with an action taken or planned by

another agency; (3) materially alter the budgetary impact of

entitlements, grants, user fees, or loan programs or the rights and

obligations of recipients thereof; or (4) raise novel legal or policy

issues arising out of legal mandates, the President's priorities, or

the principles set forth in the Executive Order.''

This regulation is not significant because it approves a testing

procedure for use in compliance monitoring and data gathering but does

not require its use. It has been determined that this rule is not a

``significant regulatory action'' under the terms of Executive Order

12866 and is therefore not subject to OMB review.

B. Unfunded Mandates Reform Act

Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), P.L.

104-4, establishes requirements for Federal agencies to assess the

effects of their regulatory actions on State, local, and tribal

governments and the private sector. Under section 202 of the UMRA, EPA

generally must prepare a written statement, including a cost-benefit

analysis, for proposed and final rules with ``Federal mandates'' that

may result in expenditures to State, local, and tribal governments, in

the aggregate, or to the private sector, of $100 million or more in any

one year. Before promulgating an EPA rule for which a written statement

is needed, section 205 of the UMRA generally requires EPA to identify

and consider a reasonable number of regulatory alternatives and adopt

the least costly, most cost-effective or least burdensome alternative

that achieves the objectives of the rule. The provisions of section 205

do not apply when they are inconsistent with applicable law. Moreover,

section 205 allows EPA to adopt an alternative other than the least

costly, most cost-effective or least burdensome alternative if the

Administrator publishes with the final rule an explanation why that

alternative was not adopted. Before EPA establishes any regulatory

requirements that may significantly or uniquely affect small

[[Page 36816]]

governments, including tribal governments, it must have developed under

section 203 of the UMRA a small government agency plan. The plan must

provide for notifying potentially affected small governments, enabling

officials of affected small governments to have meaningful and timely

input in the development of EPA regulatory proposals with significant

Federal intergovernmental mandates, and informing, educating, and

advising small governments on compliance with the regulatory

requirements.

Today's proposed rule contains no Federal mandates (under the

regulatory provisions of title II of the UMRA) for State, local, or

Tribal governments or the private sector. The proposed rule would

impose no enforceable duty on any State, local or Tribal governments or

the private sector. This rule proposes alternative analytical tests

procedures which merely standardize the procedures when testing is

otherwise required by a regulatory agency. Therefore, the proposed rule

is not subject to the requirements of sections 202 and 205 of the UMRA.

EPA invites comment on its conclusions regarding whether alternate test

procedures constitute a federal mandate.

EPA has determined that this proposed rule contains no regulatory

requirements that might significantly or uniquely affect small

governments and thus this proposed rule is not subject to the

requirements of section 203 of UMRA. This proposed rule would simply

approve an additional test procedure for measurements that may be

required under the CWA.

C. Regulatory Flexibility Act

Pursuant to section 605(b) of the Regulatory Flexibility Act, 5

U.S.C. 605(b), the Administrator certifies that this rule will not have

a significant economic impact on a substantial number of small

entities. This regulation simply approves an additional testing

procedure for the measurement of available cyanide which may be

required in the implementation of the CWA.

D. Paperwork Reduction Act

In accordance with the Paperwork Reduction Act of 1980, 44 U.S.C.

3501 et seq., EPA must submit an information collection request

covering information collection requirements in proposed rules to the

Office of Management and Budget (OMB) for review and approval. This

rule contains no information collection requirements. Therefore,

preparation of an information collection request to accompany this rule

is unnecessary.

E. National Technology Transfer and Advancement Act of 1995

Under Sec. 12(d) of the National Technology Transfer and

Advancement Act (``NTTAA''), the Agency is required to use voluntary

consensus standards in its regulatory activities unless to do so would

be inconsistent with applicable law or otherwise impractical. Voluntary

consensus standards are technical standards (e.g., material

specifications, test methods, sampling procedures, business practice,

etc.) that are developed or adopted by voluntary consensus standard

bodies. Where available and potentially applicable standards are not

used by EPA, the Act requires the Agency to provide Congress, through

the Office of Management and Budget (OMB), an explanation for the

reasons for not using such standards.

Proposal of Method OIA-1677 is the result of a collaborative effort

between OI Analytical, a private sector vendor, and EPA. Method OIA-

1677 applies the innovative technologies of ligand exchange, flow

injection analysis (FIA), and amperometric detection to the

determination of available cyanide, a pollutant regulated under the

Clean Water Act. Approval of Method OIA-1677 would allow use of these

technologies to overcome interference problems commonly encountered in

the determination of available cyanide and would thereby provide more

reliable results for compliance determinations.

EPA's search of the technical literature revealed that there are no

consensus methods for determination of ``available cyanide by flow

injection/ligand exchange/amperometry,'' although ASTM is in the

balloting process for approval of such a method. The ASTM method may

differ slightly from Method OIA-1677. If ASTM approves such a method

prior to final action on today's proposal and EPA determines that the

ASTM method is suitable for compliance monitoring and other purposes,

EPA may take final action to promulgate the ASTM method (without

additional invitation for public comment in the Federal Register) when

the Agency takes final action to promulgate Method OIA-1677 if the ASTM

method ultimately developed does not differ significantly from Method

OIA-1677. EPA invites public comments on the Agency's proposed method

as well as on any other existing, potentially applicable voluntary

consensus standards which the Agency should consider for the

determination of available cyanide or cyanide amenable to chlorination

by flow injection/ligand exchange/amperometry.

F. Executive Order 13045

The Executive Order, ``Protection of Children from Environmental

Health Risks and Safety Risks'' (62 FR 19885, April 23, 1997) applies

to any rule that EPA determines (1) ``economically significant'' as

defined under Executive Order 12866, and (2) concerns an environmental

health or safety risk that EPA has reason to believe may have a

disproportionate effect on children. If the regulatory action meets

both criteria, the Agency must evaluate the environmental health or

safety effects of the planned rule on children; and explain why the

planned regulation is preferable to other potentially effective and

reasonably feasible alternatives considered by the Agency.

EPA interprets the E.O. 13045 as encompassing only those regulatory

actions that are risk based or health based, such that the analysis

required under section 5-501 of the E.O. has the potential to influence

the regulation. This rule is not subject to E.O. 13045 because it does

not involve decisions regarding environmental health or safety risks.

VII. Request for Comments

EPA requests public comments and information on this proposed rule.

Specifically, EPA invites comment on the appropriateness Method OIA-

1677 for cyanide analysis, the utility of Method OIA-1677 for

monitoring, the QC acceptance criteria in Method OIA-1677, and the

comparability of results with CATC methods and results produced by

Method OIA-1677, and EPA's proposed decision not to withdraw other,

existing approved methods for determination of available cyanide by

CATC.

List of Subjects in 40 CFR Part 136

Environmental protection, Analytical methods, Monitoring, Reporting

and record keeping requirements, Waste treatment and disposal, Water

pollution control.

Dated: June 29, 1998.

Carol M. Browner,

Administrator.

In consideration of the preceding, USEPA proposes to amend title

40, chapter I of the Code of Federal Regulations as follows:

PART 136--[AMENDED]

1. The authority citation for part 136 continues to read as

follows:

Authority: Secs. 301, 304(h), 307, and 501(a) Pub. L. 95-217,

Stat. 1566, et seq. (33 U.S.C. 1251, et seq.) (The Federal Water

Pollution Control Act Amendments of 1972

[[Page 36817]]

as amended by the Clean Water Act of 1977 and the Water Quality Act

of 1987), 33 U.S.C. 1314 and 1361; 86 Stat. 816, Pub. L. 92-500; 91

Stat. 1567, Pub. L. 92-217; Stat. 7, Pub. L. 100-4 (The ``Act'').

2. Section 136.3, paragraph (a), Table IB is amended by revising

entry 24 and adding a new footnote 42 to read as follows:

Sec. 136.3 Identification of test procedures.

(a) * * *

Table IB.--List of Approved Inorganic Test Procedures

--------------------------------------------------------------------------------------------------------------------------------------------------------

Reference (method number or page)

---------------------------------------------------------------------------------------------------------------------

Parameter units and method Standard methods 18th

EPA1,35 ed. ASTM USGS 2 Other

--------------------------------------------------------------------------------------------------------------------------------------------------------

* * * * * * *

24. Available Cyanide, mg/L ..................... 335.14500-CN G....... D2036-91(B) .................... .........................

Cyanide amenable to chlorination

(CATC), Manual distillation with

MgCl2 followed by titrimetry or

spectrophotometry.

Available, Flow injection and ..................... ..................... ..................... .................... OIA-1677.42

ligand exchange, followed by

amperometry.

* * * * * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------

Table IB Notes:

\1\ ``Methods for Chemical Analysis of Water and Wastes'', Environmental Protection Agency, Environmental Monitoring Systems Laboratory-Cincinnati (EMSL-

C1), EPA-600/4-79-020, Revised March 1983 and 1979 where applicable.

\2\ Fishman, M.J., et al, ``Methods for Analysis of Inorganic Substances in Water and Fluvial Sediments,'' U.S. Department of the Interior, Techniques

of Water--Resource Investigations of the U.S. Geological Survey, Denver, CO, Revised 1989, unless otherwise stated.

* * * * * * *

\35\ Precision and recovery statements for the atomic absorption direct aspiration and graphite furnace methods, and for the spectrophotometric SDDC

method for arsenic are provided in Appendix D of the part titled, ``Precision and Recovery Statements for Methods for Measuring Metals''.

* * * * * * *

\42\ Cyanide, Available, Method OIA-1677 (Flow Injection Analysis/Ligand Exchange), ALPKEM, a division of OI Analytical, Box 648, Wilsonville, OR 97070.

* * * * * * *

3. In part 136, appendix A is amended by adding Method OIA-1677

following Method 1625 to read as follows:

Appendix A to part 136--Methods for Organic Chemical Analysis of

Municipal and Industrial Wastewater

* * * * *

Method OIA-1677, November 1997--Available Cyanide by Flow Injection,

Ligand Exchange, and Amperometry

1.0 Scope and Application

1.1 This method is for determination of available cyanide in

water and wastewater by flow injection, ligand exchange, and

amperometric titration. The method is for use in EPA's data

gathering and monitoring programs associated with the Clean Water

Act, Resource Conservation and Recovery Act, Comprehensive

Environmental Response, Compensation and Liability Act, and Safe

Drinking Water Act.

1.2 Cyanide ion (CN-), hydrogen cyanide in water

(HCNaq), and the cyano-complexes of zinc, copper,

cadmium, mercury, nickel, and silver may be determined by this

method (see Section 17.2.1).

1.3 The presence of polysulfides and colloidal material may

prove intractable for application of this method.

1.4 The method detection limit (MDL) is 0.5 g/L and

the minimum level (ML) is 2.0 g/L. The dynamic range is

approximately 2.0 g/L (ppb) to 5.0 mg/L (ppm) cyanide ion

using a 200 L sample loop volume. Higher concentrations can

be determined by dilution of the original sample or by reducing

volume of the sample loop.

1.5 This method is for use by analysts experienced with flow

injection equipment or under close supervision of such qualified

persons.

1.6 The laboratory is permitted to modify the method to

overcome interferences or to lower the cost of measurements,

provided that all performance criteria in this method are met.

Requirements for establishing method equivalency are given in

Section 9.1.2.

2.0 Summary of Method

2.1 The analytical procedure employed for determination of

available cyanide is divided into two parts: sample pretreatment and

cyanide detection. In the pretreatment step, ligand-exchange

reagents are added at room temperature to 100 mL of a cyanide-

containing sample. The ligand-exchange reagents form

thermodynamically stable complexes with the transition metal ions

listed in Section 1.2, resulting in the release of cyanide ion from

the metal-cyano complexes. Cyanide detection is accomplished using a

flow-injection analysis (FIA) system (Reference 15.6). A 200-

L aliquot of the pre-treated sample is injected into the

flow injection manifold of the system. The addition of hydrochloric

acid converts cyanide ion to hydrogen cyanide (HCN) that passes

under a gas diffusion membrane. The HCN diffuses through the

membrane into an alkaline receiving solution where it is converted

back to cyanide ion. The cyanide ion is monitored amperometrically

with a silver working electrode, silver/silver chloride reference

electrode, and platinum/stainless steel counter electrode, at an

applied potential of zero volt. The current generated is

proportional to the cyanide concentration present in the original

sample. Total analysis time is approximately two minutes.

2.2 The quality of the analysis is assured through reproducible

calibration and testing of the FIA system.

2.3 A flow diagram of the FIA system is shown in Figure 1.

BILLING CODE 6560-50-P

[[Page 36818]]

[GRAPHIC] [TIFF OMITTED] TP07JY98.023

BILLING CODE 6560-50-C

3.0 Definitions.

Definitions for terms used in this method are given in the

glossary at the end of the method.

4.0 Interferences.

4.1 Solvents, reagents, glassware, and other sample-processing

hardware may yield artifacts that affect results. Specific selection

of reagents or purification of these reagents may be required.

4.2 All materials used in the analysis shall be demonstrated to

be free from interferences under the conditions of analysis by

running laboratory blanks as described in Section 9.4.

4.3 Glassware is cleaned by washing in hot water containing

detergent, rinsing with tap and reagent water, and drying in an area

free from interferences.

4.4 Interferences extracted from samples will vary considerably

from source to source, depending upon the diversity of the site

being sampled.

4.5 Sulfide is a positive interferent in this method

(References 15.3 and 15.4), because an acidified sample containing

sulfide liberates hydrogen sulfide that is passed through the

membrane and produces a signal at the silver electrode. In addition,

sulfide ion reacts with cyanide ion in solution to reduce its

concentration over time. To overcome this interference, the sulfide

ion must be precipitated with lead ion immediately upon sample

collection. Sulfide ion and lead sulfide react with cyanide ion to

form thiocyanate which is not detected in the analytical system.

Tests have shown (Reference 15.7) that if lead carbonate is used for

sulfide precipitation, the supernate containing cyanide must be

filtered immediately to avoid loss of cyanide through reaction with

precipitated lead sulfide (Section 8.2.1).

4.6 Though not interferences, substances that react with

cyanide should also be removed from samples at time of collection.

These substances include water soluble aldehydes that form

cyanohydrins and oxidants such as hypochlorite and sulfite. Water

soluble aldehydes react with cyanide to form cyanohydrins that are

not detected by the analytical system; hypochlorite and sulfite

oxidize cyanide to non-volatile forms. Procedures for the removal of

these substances are provided in Sections 8.2.2 and 8.2.3.

4.7 Tests conducted using samples containing large amounts of

colloids indicate that cyanide losses are rapid when colloids are

present. Filtration can be used to remove colloids, but may have an

adverse effect on measured cyanide levels. This method should not be

applied to samples with large amounts of colloids unless the

laboratory is able to demonstrate that cyanide concentration

measurements in a sample are not affected by filtration.

5.0 Safety.

5.1 The toxicity or carcinogenicity of each compound or

reagent used in this method has not been precisely determined;

however, each chemical compound should be treated as a potential

health hazard. Exposure to these compounds should be reduced to the

lowest possible level.

5.2 Cyanides and cyanide solutions.

WARNING: The cyanide ion, hydrocyanic acid, all cyanide salts,

and most metal-cyanide complexes are extremely dangerous. As a

contact poison, cyanide need not be ingested to produce toxicity.

Also, cyanide solutions produce fatally toxic hydrogen cyanide gas

when acidified. For these reasons, it is mandatory that work with

cyanide be carried out in a well-ventilated hood by properly trained

personnel wearing adequate protective equipment.

5.3 Sodium hydroxide solutions.

CAUTION: Considerable heat is generated upon dissolution of

sodium hydroxide in water. It may be advisable to cool the container

in an ice bath when preparing sodium hydroxide solutions.

5.4 Unknown samples may contain high concentrations of volatile

toxic compounds. Sample containers should be opened in a hood and

handled with gloves to prevent exposure.

5.5 This method does not address all safety issues associated

with its use. The laboratory is responsible for maintaining a safe

work environment and a current awareness file of OSHA regulations

regarding the safe handling of the chemicals specified in this

method. A reference file of material safety data sheets (MSDSs)

should be available to all personnel involved in these analyses.

Additional information on laboratory safety can be found in

References 15.8 and 15.9.

6.0 Equipment and Supplies

Note: Brand names, suppliers, and part numbers are for

illustrative purposes only. No endorsement is implied. Equivalent

performance may be achieved using apparatus and materials other than

those specified here, but demonstration of equivalent performance

that meets the requirements of this method is the responsibility of

the laboratory.

6.1 Flow injection analysis (FIA) system--ALPKEM Model 3202

(Reference 15.5), or equivalent, consisting of the following:

6.1.1 Injection valve capable of injecting 40 to 300 L

samples.

6.1.2 Gas diffusion manifold with a microporous

Teflon or polypropylene membrane.

6.1.3 Amperometric detection system with:

6.1.3.1 Silver working electrode.

6.1.3.2 Ag/AgCl reference electrode.

6.1.3.3 Pt/stainless steel counter electrode.

6.1.3.4 Applied potential of 0.0 volt.

6.2 Sampling equipment--Sample bottle, amber glass, 1.1-L, with

polytetrafluoroethylene (PTFE)-lined cap. Clean by washing with

detergent and water, rinsing with two aliquots of reagent water, and

drying by baking at 110-150 deg.C for one hour minimum.

6.3 Standard laboratory equipment including volumetric flasks,

pipettes, syringes, etc. all cleaned, rinsed and dried per bottle

cleaning procedure in Section 6.2.

[[Page 36819]]

7.0 Reagents and Standards.

7.1 Reagent water--Water in which cyanide and potentially

interfering substances are not detected at the MDL of this method.

It may be generated by any one of the methods listed below. Reagent

water generated by these methods shall be tested for purity

utilizing the procedure in Section 11.

7.1.1 Activated carbon--Pass distilled or deionized water

through an activated carbon bed (Calgon Filtrasorb-300 or

equivalent).

7.1.2 Water purifier--Pass distilled or deionized water through

a purifier (Millipore Super Q, or equivalent).

7.2 Sodium hydroxide--ACS reagent grade.

7.3 Potassium cyanide--ACS reagent grade.

7.4 Mercury (II) cyanide, 99% purity--Aldrich

Chemical Company Catalog No. 20,814-0, or equivalent.

7.5 Silver nitrate--ACS reagent grade. Aldrich Chemical Company

Catalog No. 20,913-9, or equivalent.

7.6 Hydrochloric acid--approximately 37%, ACS reagent grade.

7.7 Preparation of stock solutions. Observe the warning in

Section 5.2.

7.7.1 Silver nitrate solution, 0.0192 N--Weigh 3.27 g of

AgNO3 into a 1-L volumetric flask and bring to the mark

with reagent water.

7.7.2 Rhodanine solution, 0.2 mg/mL in acetone--Weigh 20 mg of

p-dimethylaminobenzal rhodanine (Aldrich Chemical Co. Catalog No.

11,458-8, or equivalent) in a 100-mL volumetric flask and dilute to

the mark with acetone.

7.7.3 Potassium cyanide stock solution, 1000 mg/L

7.7.3.1 Dissolve approximately 2 g (approximately 20 pellets)

of sodium hydroxide in approximately 500 mL of reagent water

contained in a 1-liter volumetric flask. Observe the caution in

Section 5.3. Add 2.51 g of potassium cyanide (Aldrich Chemical Co.

Catalog No. 20,781-0, or equivalent), dilute to one liter with

reagent water, and mix well. Store KCN solution in an amber glass

container at 0-4 deg.C.

7.7.3.2 Standardize the KCN solution (Section 7.7.3.1) by adding

0.5 mL of rhodanine solution (Section 7.7.2) to 25 mL of KCN

solution and titrating with AgNO3 solution (Section

7.7.1) until the color changes from canary yellow to a salmon hue.

Based on the determined KCN concentration, dilute the KCN solution

to an appropriate volume so the final concentration is 1.00 g/L,

using the following equation:

Equation 1

x x v=1g/L x 1L

Where:

x=concentration of KCN solution determined from titrations

v=volume of KCN solution needed to prepare 1 L of 1 g/L KCN solution

If the concentration is not 1.00 g/L, correct the intermediate

and working calibration concentrations accordingly.

7.7.4 1M sodium hydroxide--Dissolve 40 g of sodium hydroxide

pellets in approximately 500 mL of reagent water in a 1-liter

volumetric flask, observing the caution in Section 5.3. Dilute to

one liter with reagent water. Store in an amber bottle at room

temperature.

7.8 Secondary standards.

7.8.1 Cyanide, 100 mg/L--Dilute 100.0 mL of cyanide stock

solution (Section 7.7.3.2) and 10 mL of 1M sodium hydroxide (Section

7.7.4) to one liter with reagent water (Section 7.1). Store in an

amber glass bottle at 0-4 deg.C.

7.8.2 Cyanide, 10 mg/L--Dilute 10.0 mL of cyanide stock

solution and 10 mL of 1M sodium hydroxide to one liter with reagent

water. Store in an amber glass bottle at 0-4 deg.C.

7.8.3 Cyanide, 1 mg/L--Dilute 1.0 mL of cyanide stock solution

and 1 mL of 1M sodium hydroxide to one liter with reagent water.

Store in an amber glass bottle at 0-4 deg.C.

7.8.4 Cyanide working calibration standard solutions (2--5000

g/L as cyanide)--Working calibration standards may be

prepared to cover the desired calibration range by adding the

appropriate volumes of secondary standards (Sections 7.8.1, 7.8.2,

7.8.3) to 100 mL volumetric flasks that contain 40 mL of reagent

water 7.1) and 1 mL of 1M sodium hydroxide (Section 7.7.4). Dilute

the solutions to 100 mL with reagent water. Prepare working

calibration standards daily. The following table provides the

quantity of secondary standard necessary to prepare working

standards of the specified concentration.

----------------------------------------------------------------------------------------------------------------

Secondary standard solution volume

-----------------------------------------------

Secondary

Secondary Secondary standard

Working calibration standard concentration (g/L) standard standard concentration

concentration concentration (section

(section (section 7.8.1) 100 mg/

7.8.3) 1 mg/L 7.8.2) 10 mg/L L

----------------------------------------------------------------------------------------------------------------

0.000........................................................... .............. .............. ..............

2.0............................................................. 0.200 .............. ..............

5.0............................................................. 0.500 0.050 ..............

10.0............................................................ 1.00 0.100 ..............

50.0............................................................ 5.00 0.500 0.050

100............................................................. 10.0 1.00 0.100

200............................................................. 20.0 2.00 0.200

500............................................................. 50.0 5.00 0.500

1000............................................................ .............. 10.0 1.00

3000............................................................ .............. 30.0 3.00

5000............................................................ .............. 50.0 5.00

----------------------------------------------------------------------------------------------------------------

If desired, the laboratory may extend the analytical working

range by using standards that cover more than one calibration range,

so long as the requirements of Section 10.3 are met.

7.9 Sample Preservation Reagents.

7.9.1 The presence of sulfide may result in the conversion of

cyanide to thiocyanate. While lead acetate test paper has been

recommended for determining the presence of sulfide in samples, the

test is generally unreliable and is typically not usable for sulfide

concentrations below approximately 1 ppm. The use of lead carbonate

(Aldrich Chemical Co. Catalog No. 33,637-8, or equivalent), followed

by immediate filtration of the sample is required whenever sulfide

ion is present. If the presence of sulfide is suspected but not

verifiable from the use of lead acetate test paper, two samples may

be collected, one without lead carbonate addition and another with

lead carbonate addition followed by immediate filtration. Analyze

both samples. If sulfide is present, the preserved sample should

contain higher levels of cyanide than the unpreserved sample. Lead

acetate test paper may be used, but should be tested for minimum

level of sulfide detection by spiking reagent water aliquots with

decreasing levels of sulfide and determining the lowest level of

sulfide detection attainable. The spiked samples are tested with

lead acetate test paper moistened with acetate buffer solution. The

buffer solution is prepared by dissolving 146 g anhydrous sodium

acetate, or 243 g sodium acetate trihydrate in 400 mL of reagent

water, followed by addition of 480 g concentrated acetic acid.

Dilute the solution to 1 L with reagent water. Each new batch of

test paper and/or acetate buffer should be tested to determine the

lowest level of sulfide ion detection prior to use.

7.9.2 Ethylenediamine solution--In a 100 mL volumetric flask,

dilute 3.5 mL pharmaceutical-grade anhydrous ethylenediamine

(Aldrich Chemical Co. Catalog No. 24,072-9, or equivalent) with

reagent water.

7.9.3 Ascorbic acid--Crystals--Aldrich Chemical Co. Catalog No.

26,855-0, or equivalent.

7.10 FIA Reagents.

[[Page 36820]]

7.10.1 Carrier and acid reagent (0.1M hydrochloric acid)--

Dilute 8 mL of concentrated hydrochloric acid to one liter with

reagent water.

7.10.2 Acceptor stock solution (5M sodium hydroxide)--Dissolve

200 grams of sodium hydroxide in 700 mL of reagent water with

stirring, observing the caution in Section 5.3. Dilute to one liter

with reagent water.

7.10.3 Acceptor reagent (0.1M sodium hydroxide)--Dilute 20 mL

of sodium hydroxide solution (Section 7.7.4) to 1000 mL with reagent

water.

7.10.4 Ligand-exchange reagent A-ALPKEM part number A001416, or

equivalent.

7.10.5 Ligand-exchange reagent B-ALPKEM part number A001417, or

equivalent.

7.11 Quality control solutions.

7.11.1 Mercury (II) cyanide stock solution (1000 mg/L as

cyanide)--Weigh 0.486 g of mercury (II) cyanide (Section 7.4) in a

100-mL volumetric flask. Add 10-20 mL of reagent water and 1 mL of

1M sodium hydroxide solution (Section 7.7.4). Swirl to mix. Dilute

to the mark with reagent water.

7.11.2 Laboratory control sample (LCS)--Place 2.00 mL of the

mercury (II) cyanide stock solution (Section 7.11.1) in a 100-mL

volumetric flask and dilute to the mark with reagent water to

provide a final cyanide concentration of 2.00 mg/L.

8.0 Sample Collection, Preservation, and Storage.

8.1 Sample collection and preservation--Samples are collected

using manual (grab) techniques and are preserved immediately upon

collection.

8.1.1 Grab sampling--Collect samples in amber glass bottles

with PTFE-lined caps cleaned according to the procedure in Section

6.2. Immediately after collection, preserve the sample using any or

all of the preservation techniques (Section 8.2), followed by

adjustment of the sample pH to 12 by addition of 1M

sodium hydroxide and refrigeration at 0-4 deg.C.

8.1.2 Compositing--Compositing is performed by combining

aliquots of grab samples only. Automated compositing equipment may

not be used because cyanide may react or degrade during the sampling

period. Preserve and refrigerate each grab sample immediately after

collection (Sections 8.1.1 and 8.2) until compositing.

8.1.3 Shipment--If the sample will be shipped by common carrier

or mail, limit the pH to a range of 12.0-12.3. (See the footnote to

40 CFR 136.3(e), Table II, for the column headed ``Preservation.'')

8.2 Preservation techniques.

8.2.1 Samples containing sulfide ion--Test samples with lead

acetate test paper (Section 7.9.1) to determine the presence or

absence of sulfide ion. If sulfide ion is present, treat the sample

with sufficient solid lead carbonate (Section 7.9.1) to remove

sulfide (as evidenced by lead acetate test paper) and immediately

filter into another sample bottle to remove precipitated lead

sulfide. If sulfide ion is suspected to be present, but its presence

is not detected by this test, two samples should be collected. One

is treated for the presence of sulfide and immediately filtered,

while the second sample is not treated for sulfide. Both samples

must be analyzed by the laboratory. (Tests conducted prior to the

interlaboratory validation of this method showed significant and

rapid losses of cyanides when lead sulfide was allowed to remain in

contact with the sample during holding times of three days and less.

As a result, the immediate filtration of samples preserved with lead

carbonate is essential (Reference 15.6).

8.2.2 Samples containing water soluble aldehydes--Treat samples

containing or suspected to contain formaldehyde, acetaldehyde, or

other water soluble aldehydes with 20 mL of 3.5% ethylenediamine

solution (Section 7.9.2) per liter of sample.

8.2.3 Samples known or suspected to contain chlorine,

hypochlorite, and/or sulfite--Treat with 0.6 g of ascorbic acid

(Section 7.9.3) per liter of sample. EPA Method 330.4 or 330.5 may

be used for the measurement of residual chlorine (Reference 15.1).

8.3 Sample holding time--Maximum holding time for samples

preserved as above is 14 days. Unpreserved samples must be analyzed

within 24 hours, or sooner if a change in cyanide concentration will

occur. (See the footnotes to Table II at 40 CFR 136.3(e).)

9.0 Quality Control.

9.1 Each laboratory that uses this method is required to

operate a formal quality assurance program (Reference 15.9). The

minimum requirements of this program consist of an initial

demonstration of laboratory capability, and the periodic analysis of

LCSs and MS/MSDs as a continuing check on performance. Laboratory

performance is compared to established performance criteria to

determine if the results of the analyses meet the performance

characteristics of the method.

9.1.1 The laboratory shall make an initial demonstration of the

ability to generate acceptable precision and accuracy with this

method. This ability is established as described in Section 9.2.

9.1.2 In recognition of advances that are occurring in

analytical technology, and to allow the laboratory to overcome

sample matrix interferences, the laboratory is permitted certain

options to improve performance or lower the costs of measurements.

Alternate determinative techniques, such as the substitution of

spectroscopic or immuno-assay techniques, and changes that degrade

method performance, are not allowed. If an analytical technique

other than the techniques specified in this method is used, that

technique must have a specificity equal to or better than the

specificity of the techniques in this method for the analytes of

interest.

9.1.2.1 Each time a modification is made to this method, the

laboratory is required to repeat the procedure in Section 9.2. If

the detection limit of the method will be affected by the change,

the laboratory must demonstrate that the MDL is equal to or less

than the MDL in Section 1.4 or one-third the regulatory compliance

level, whichever is greater. If calibration will be affected by the

change, the laboratory must recalibrate the instrument per Section

10.3.

9.1.2.2 The laboratory is required to maintain records of

modifications made to this method. These records include the

information in this subsection, at a minimum.

9.1.2.2.1 The names, titles, addresses, and telephone numbers

of the analyst(s) who performed the analyses and modification, and

of the quality control officer who witnessed and will verify the

analyses and modification.

9.1.2.2.2 A narrative stating the reason(s) for the

modification.

9.1.2.2.3 Results from all quality control (QC) tests comparing

the modified method to this method including:

(a) calibration (Section 10.3)

(b) calibration verification (Section 9.5)

(c) initial precision and recovery (Section 9.2)

(d) analysis of blanks (Section 9.4)

(e) laboratory control sample (Section 9.6)

(f) matrix spike and matrix spike duplicate (Section 9.3)

(g) MDL (Section 1.4)

9.1.2.2.4 Data that will allow an independent reviewer to

validate each determination by tracing the instrument output (peak

height, area, or other signal) to the final result. These data are

to include:

(a) sample numbers and other identifiers

(b) analysis dates and times

(c) analysis sequence/run chronology

(d) sample weight or volume

(e) sample volume prior to each cleanup step, if applicable

(f) sample volume after each cleanup step, if applicable

(g) final sample volume prior to injection (Sections 10 and 11)

(h) injection volume (Sections 10 and 11)

(i) dilution data, differentiating between dilution of a sample

or modified sample (Sections 10 and 11)

(j) instrument and operating conditions

(k) other operating conditions (temperature, flow rates, etc.)

(l) detector (operating condition, etc.)

(m) printer tapes, disks, and other recording of raw data

(n) quantitation reports, data system outputs, and other data

necessary to link raw data to the results reported

9.1.3 Analyses of matrix spike and matrix spike duplicate

samples are required to demonstrate method accuracy and precision

and to monitor matrix interferences (interferences caused by the

sample matrix). The procedure and QC criteria for spiking are

described in Section 9.3.

9.1.4 Analyses of blanks are required to demonstrate freedom

from contamination and that the compounds of interest and

interfering compounds have not been carried over from a previous

analysis. The procedures and criteria for analysis of a blank are

described in Section 9.4.

9.1.5 The laboratory shall, on an ongoing basis, demonstrate

through the analysis of the LCS (Section 7.11.2) that the analysis

system is in control. This procedure is described in Section 9.6.

9.1.6 The laboratory should maintain records to define the

quality of data that is

[[Page 36821]]

generated. Development of accuracy statements is described in

Sections 9.3.8 and 9.6.3.

9.1.7 Accompanying QC for the determination of cyanide is

required per analytical batch. An analytical batch is a set of

samples analyzed at the same time, to a maximum of 10 samples. Each

analytical batch of 10 or fewer samples must be accompanied by a

laboratory blank (Section 9.4), an LCS (Section 9.6), and a matrix

spike and matrix spike duplicate (MS/MSD, Section 9.3), resulting in

a minimum of five analyses (1 sample, 1 blank, 1 LCS, 1 MS, and 1

MSD) and a maximum of 14 analyses (10 samples, 1 blank, 1 LCS, 1 MS,

and 1 MSD) in the batch. If greater than 10 samples are analyzed at

one time, the samples must be separated into analytical batches of

10 or fewer samples.

9.2 Initial demonstration of laboratory capability

9.2.1 Method Detection Limit (MDL)--To establish the ability to

detect cyanide at low levels, the laboratory shall determine the MDL

per the procedure in 40 CFR 136, Appendix B (Reference 15.4) using

the apparatus, reagents, and standards that will be used in the

practice of this method. An MDL less than or equal to the MDL listed

in Section 1.4 must be achieved prior to practice of this method.

9.2.2 Initial Precision and Recovery (IPR)--To establish the

ability to generate acceptable precision and accuracy, the

laboratory shall perform the following operations:

9.2.2.1 Analyze four samples of the LCS (Section 7.11.2)

according to the procedure beginning in Section 10.

9.2.2.2 Using the results of the set of four analyses, compute

the average percent recovery (X) and the standard deviation of the

percent recovery (s) for cyanide. Use Equation 2 for calculation of

the standard deviation of the percent recovery.

Equation 2

[GRAPHIC] [TIFF OMITTED] TP07JY98.024

Where:

n = Number of samples

x = Percent recovery in each sample

9.2.3 Compare s and X with the acceptance criteria specified in

Table 1. If s exceeds the precision limit or X falls outside the

range for recovery, system performance is unacceptable and the

problem must be found and corrected before analyses can begin.

9.3 Matrix spike/matrix spike duplicate (MS/MSD)--The

laboratory shall spike, in duplicate, a minimum of 10 percent of all

samples (one sample in duplicate in each batch of ten samples) from

a given discharge.

9.3.1 The concentration of the spike in the sample shall be

determined as follows:

9.3.1.1 If, as in compliance monitoring, the concentration of

cyanide in the sample is being checked against a regulatory

concentration limit, the spiking level shall be at that limit or at

1 to 5 times higher than the background concentration of the sample

(determined in Section 9.3.2), whichever concentration is higher.

9.3.1.2 If the concentration of cyanide in a sample is not

being checked against a limit, the spike shall be at the

concentration of the LCS or at 1 to 5 times higher than the

background concentration, whichever concentration is higher.

9.3.2 Analyze one sample aliquot out of each set of ten

samples from each discharge according to the procedure beginning in

Section 11 to determine the background concentration (B) of cyanide.

9.3.2.1 Spike this sample with the amount of mercury (II)

cyanide stock solution (Section 7.11.1) necessary to produce a

cyanide concentration in the sample of 2 mg/L. If necessary, prepare

another stock solution appropriate to produce a level in the sample

at the regulatory compliance limit or at 1 to 5 times the background

concentration (per Section 9.3.1).

9.3.2.2 Spike two additional sample aliquots with the spiking

solution and analyze these aliquots to determine the concentration

after spiking (A).

9.3.3 Calculate the percent recovery of cyanide in each aliquot

using Equation 3.

Equation 3

100 (A-B)

p = --------------------

T

Where:

P = Percent recovery

A = Measured concentration of cyanide after spiking

B = Measured background concentration of cyanide

T = True concentration of the spike

9.3.4 Compare the recovery to the QC acceptance criteria in

Table 1. If recovery is outside of the acceptance criteria, and the

recovery of the LCS in the ongoing precision and recovery test

(Section 9.6) for the analytical batch is within the acceptance

criteria, an interference is present. In this case, the result may

not be reported for regulatory compliance purposes.

9.3.5 If the results of both the MS/MSD and the LCS test fail

the acceptance criteria, the analytical system is judged to be out

of control. In this case, the problem shall be identified and

corrected, and the analytical batch reanalyzed.

9.3.6 Calculate the relative percent difference (RPD) between

the two spiked sample results (Section 9.3, not between the two

percent recoveries) using Equation 4.

Equation 4

[GRAPHIC] [TIFF OMITTED] TP07JY98.026

Where:

RPD = Relative percent difference

D1 = Concentration of cyanide in the spiked sample

D2 = Concentration of cyanide in the spiked duplicate

sample

9.3.7 Compare the precision to the RPD criteria in Table 1. If

the RPD is greater than the acceptance criteria, the analytical

system is judged to be out of control, and the problem must be

immediately identified and corrected, and the analytical batch

reanalyzed.

9.3.8 As part of the QC program for the laboratory, method

precision and accuracy for samples should be assessed and records

should be maintained. After the analysis of five spiked samples in

which the recovery passes the test in Section 9.3.4, compute the

average percent recovery (Pa) and the standard deviation

of the percent recovery (sp). Express the accuracy

assessment as a percent recovery interval from Pa -

2sp to Pa + 2sp. For example, if

Pa = 90% and sp = 10% for five analyses, the

accuracy interval is expressed as 70--110%. Update the accuracy

assessment on a regular basis (e.g., after each five to ten new

accuracy measurements).

9.4 Laboratory blanks--Laboratory reagent water blanks are

analyzed to demonstrate freedom from contamination.

9.4.1 Analyze a reagent water blank initially (i.e., with the

tests in Section 9.2) and with each analytical batch. The blank must

be subjected to the same procedural steps as a sample.

9.4.2 If cyanide is detected in the blank at a concentration

greater than the ML, analysis of samples is halted until the source

of contamination is eliminated and a blank shows no evidence of

contamination.

9.5 Calibration verification--Verify calibration of the

analytical equipment before and after each analytical batch of 14 or

fewer measurements. (The 14 measurements will normally be 10

samples, 1 reagent blank, 1 LCS, 1 MS, and 1 MSD). Verification is

accomplished by analyzing the mid-range calibration standard and

verifying that it is within the QC acceptance criteria for recovery

in Table 1. (The concentration of the calibration verification

depends on the calibration range being used.) Failure to verify

calibration within the acceptance criteria requires recalibration of

the analysis system.

9.6 Laboratory control sample (LCS)--To demonstrate that the

analytical system is in control, and acceptable precision and

accuracy is being maintained with each analytical batch, the

laboratory shall perform the following operations.

9.6.1 Analyze a LCS (Section 7.11.2) with each analytical batch

according to the procedure in Section 10.

9.6.2 If the results for the LCS are within the acceptance

criteria specified in Table 1, analysis of the batch may continue.

If, however, the concentration is not within this range, the

analytical process is not in control. In this event, correct the

problem, repeat the LCS test, and reanalyze the batch.

9.6.3 The laboratory should add results that pass the

specification in Section 9.6.2 to IPR and previous LCS data and

update QC charts to form a graphic representation of continued

laboratory performance. The laboratory should also develop a

statement of laboratory data quality for cyanide by calculating the

average percent recovery (R) and the standard deviation of the

percent recovery (Sr). Express the accuracy as a recovery

interval from R - 2sr to R + 2sr. For example,

if R = 95% and sr = 5%, the accuracy is 85% to 105%.

9.7 Reference Sample--To demonstrate that the analytical system

is in control, the

[[Page 36822]]

laboratory should periodically test an external reference sample,

such as a Standard Reference Material (SRM) if an SRM is available

from the National Institutes of Standards and Technology (NIST). The

reference sample should be analyzed quarterly, at a minimum.

Corrective action should be taken if the measured concentration

significantly differs from the stated concentration.

10.0 Calibration and Standardization.

This section describes the procedure to calibrate and

standardize the FIA system prior to cyanide determination.

10.1 Instrument setup.

10.1.1 Set up the FIA system and establish initial operating

conditions necessary for determination of cyanide. If the FIA system

is computerized, establish a method for multi-point calibration and

for determining the cyanide concentration in each sample.

10.1.2 Verify that the reagents are flowing smoothly through

the FIA system and that the flow cell is purged of air bubbles.

10.2 Instrument Stabilization

10.2.1 Load a 10 mg/L KCN standard (Section 7.8.2) into the

sampling valve and inject into the FIA system.

10.2.2 Continue to inject 10 mg/L KCN standards until 3

successive peak height or area results are within 2% RSD, indicating

that the electrode system is stabilized.

10.2.3 Following stabilization, inject the highest

concentration calibration standard until 3 successive peak height or

area results are within 2% RSD indicating stabilization at the top

of the calibration range.

10.3 External standard calibration.

10.3.1 Inject each of a minimum of 3 calibration standards. One

of the standards should be at the minimum level (ML) unless

measurements are to be made at higher levels. The other

concentrations should correspond to the expected range of

concentrations found in samples or should define the working range

of the FIA system.

10.3.2 Using injections of a constant volume, analyze each

calibration standard according to Section 11 and record peak height

or area responses against the concentration. The results can be used

to prepare a calibration curve. Alternatively, if the ratio of

response to amount injected (calibration factor) is constant over

the working range (L of ligand-

exchange reagent Part B (Section 7.10.5), 50 L of ligand-

exchange reagent Part A (Section 7.10.4), and mix thoroughly. Load

the sample, standard, or blank into the sample loop.

Note: The ligand-exchange reagents, when added to 100 mL of

sample at the specified volume, will liberate cyanide from metal

complexes of intermediate stability up to 5 mg/L cyanide ion. If

higher concentrations are anticipated, add additional ligand-

exchange reagent, as appropriate, or dilute the sample.

11.1.3 Inject the sample and begin data collection. When data

collection is complete, analyze the next sample, standard or blank

in the batch until analyses of all samples in the batch are

completed.

12.0 Data Analysis and Calculations.

12.1 Calculate the concentration of material in the sample,

standard or blank from the peak height or area using the calibration

curve or calibration factor determined in Section 10.3.

12.2 Reporting.

12.2.1 Samples--Report results to three significant figures for

cyanide concentrations found above the ML (Section 1.4) in all

samples. Report results below the ML as g/L given in Section

1.4 (Reference 15.12).

13.2 Data obtained from single laboratory testing of the method

are summarized in Table 2 and show recoveries and reproducibility

for ``free'' forms of cyanide, including the recovery and

reproducibility of silver, nickel, mercurous and mercuric cyanide

species. Determination of these species tends to be problematic with

other methods for the determination of available cyanide. As it is

the case with other methods used for available cyanide, iron cyanide

species were not recovered and recoveries for gold and cobalt

species were zero or very low. The complete results from the single

laboratory study are available in the Report of the Draft OIA Method

1677 Single Laboratory Validation Study (Reference 15.11).

13.3 Listed in Table 1 are the QC acceptance criteria developed

from an interlaboratory validation study of this method. This study

was conducted following procedures specified in the Guide to Method

Flexibility and Approval of EPA Water Methods (Reference 15.10). In

this study, a total of nine laboratories performed analyses for

various water matrices. Table 3 shows a summary of the

interlaboratory results which include the accuracy and precision

data as % recoveries and relative standard deviations. In addition

to spikes of easily dissociable cyanides, some samples contained

known amounts of cyanides that are not recoverable (e.g., Pt and Fe

complexes) and thiocyanate was spiked to one sample to investigate

the potential for interference. The complete study results are

available in the Report of the Draft OIA Method 1677 Interlaboratory

Validation Study (Reference 15.12).

14.0 Pollution Prevention and Waste Management.

14.1 It is the laboratory's responsibility to comply with all

federal, State, and local regulations governing waste management,

particularly the hazardous waste identification rules and land-

disposal restrictions. In addition, it is the laboratory's

responsibility to protect air, water, and land resources by

minimizing and controlling all releases from fume hoods and bench

operations. Also, compliance is required with any sewage discharge

permits and regulations.

14.2 Samples containing cyanide, certain metals, and acids at a

pH of less than 2 are hazardous and must be treated before being

poured down a drain or must be handled as hazardous waste.

14.3 For further information on waste management, consult Less

is Better: Laboratory Chemical Management for Waste Reduction,

Section 15.8.

15.0 References.

15.1 Environmental Monitoring Systems Laboratory. EPA Method

335.1. In: Methods for the Chemical Analysis of Water and Wastes

(EPA/600/4-79-020). Environmental Protection Agency, Cincinnati,

Ohio. Revised March 1983.

15.2 American Public Health Association, American Waterworks

Association, Water Pollution Control Board. Methods Section 4500-CN

in Standard Methods for the Examination of Water and Wastewater,

19th Edition. American Public Health Association, Washington, DC,

1995.

15.3 Ingersol, D.; Harris, W.R.; Bomberger, D.C.; Coulson, D.M.

Development and Evaluation Procedures for the Analysis of Simple

Cyanides, Total Cyanides, and Thiocyanate in Water and Waste Water

(EPA-600/4-83-054), 1983.

15.4 Code of Federal Regulations, Title 40, Part 136, Appendix

B. U.S. Government Printing Office, Washington, D.C., 1994.

15.5 ALPKEM CNSolution Model 3202 Manual. Available from

ALPKEM, a division of OI Analytical, Box 648, Wilsonville, OR 97070.

15.6 Milosavljevic, E.B.; Solujic, L.; Hendrix, J.L.

Environmental Science and Technology, Vol. 29, No. 2, 1995, pp 426-

430.

15.7 Wilmont, J.C.; Solujic, L.; Milosavljevic, E. B.; Hendrix,

J.L.; Reader, W.S. Analyst, June 1996, Vol. 121, pp 799-801.

Formation of Thiocyanate During Removal of Sulfide as Lead Sulfide

Prior to Cyanide Determination.

15.8 Less is Better: Laboratory Chemical Management for Waste

Reduction. Available from the American Chemical Society, Department

of Government Regulations and Science Policy, 1155 16th Street, NW,

Washington, DC 20036.

15.9 Handbook for Analytical Quality Control in Water and

Wastewater Laboratories (EPA-600/4-79-019), USEPA, NERL, Cincinnati,

Ohio 45268 (March 1979).

15.10 Guide to Method Flexibility and Approval of EPA Water

Methods, December, 1996, (EPA-821-D-96-004). Available from the

National Technical Information Service (PB97-117766).

15.11 Report of the Draft OIA Method 1677 Single Laboratory

Validation Study, November 1996. Available from ALPKEM, a division

of OI Analytical, Box 648, Wilsonville, OR 97070.

[[Page 36823]]

15.12 Report of the Draft OIA Method 1677 Interlaboratory

Validation Study, March 1997. Available from ALPKEM, a division of

OI Analytical, Box 648, Wilsonville, OR 97070.

16.0 Tables

Table 1.--Quality Control Acceptance Criteria

------------------------------------------------------------------------

Required

Criterion recovery range Precision

(%)

------------------------------------------------------------------------

Initial precision and recovery.......... 92-122 g/mL CN- m>g/mL CN-

------------------------------------------------------------------------

[Zn(CN)4]2-................................. 97.4 (0.7) 98.5 (0.7)

[Cd(CN)4]2-................................. 100.0 (0.8) 100.0 (0.2)

[Cu(CN)4]2-................................. 100.9 (1.3) 99.0 (0.6)

[Ag(CN)4]3-................................. 101.8 (0.9) 100.0 (0.5)

[Ni(CN)4]2-................................. 104.3 (0.2) 103.0 (0.5)

[Hg(CN)4]2-................................. 100.0 (0.6) 99.0 (0.3)

Hg(CN)2..................................... 103.4 (0.4) 98.0 (0.3)

[Fe(CN)4]4-................................. 0.0 0.0

[Fe(CN)6]3-................................. 0.0 0.0

[Au(CN)2]-.................................. \2\ 1.3

(0.0) 0.0

[Co(CN)6]3-................................. \2\ 2.9

(0.0) \2\ 2.0

(0.0)

------------------------------------------------------------------------

\1\ Values are % recoveries; numbers in parentheses are percent relative

standard deviations.

\2\ Commercial product contains some free cyanide.

Table 3.--Cyanide Recoveries From Various Aqueous Matrices

----------------------------------------------------------------------------------------------------------------

Sample CN Average %

Sample concentration Added CN1 concentration recovery % RSD

----------------------------------------------------------------------------------------------------------------

Reagent water w/0.01M NaOH........ 0 g/L 100 g/L as KCN.. 108 4.0

POTW secondary effluent........... 3.0 g/L 100 g/L as KCN; 102 7.0

2 mg/L as [Pt(CN)6]4-.

Petroleum Refinery Secondary 9.9 g/L 2 mg/L as KCN; 5 mg/L as 87 21

Effluent. [Fe(CN)6]4-.

Coke Plant Secondary Effluent..... 14.0 g/L 50 g/L as KCN... 95 4.0

Rolling Mill Direct Filter 4.0 g/L None..................... 80 41

Effluent.

Metals Finishing Indirect Primary 1.0 g/L 200 g/L as KCN; 92 16

Effluent. 2 mg/L as KSCN.

Reagent water w/0.01M NaOH........ 0 g/L 200 g/L as KCN.. 101 8.0

Reagent water w/0.01M NaOH........ 0 g/L 10 mg/L as KCN; 10 mg/L 103 2.0

as [Pt(CN)6]4-.

Mining Tailing Pond Effluent...... 842 g/L 4 mg/L as KCN............ 98 3.0

----------------------------------------------------------------------------------------------------------------

\1\ Cyano-complexes of Pt and Fe were added to the POTW and petroleum refinery effluents, respectively; and

thiocyanate was added to the metals finishing effluent to demonstrate that the FI/LE system does not determine

these forms of cyanide.

17.0 Glossary of Definitions and Purposes.

The definitions and purposes are specific to this method but

have been conformed to common usage as much as possible.

17.1 Units of weights and measures and their abbreviations

17.1.1 Symbols.

deg.C degrees Celsius

% percent

plus or minus

greater than or equal to

17.1.2 Alphabetical characters.

g gram

L liter

mg milligram

mg/L milligram per liter

g microgram

g/L microgram per liter

mL milliliter

ppm parts per million

ppb parts per billion

M molar solution

17.2 Definitions.

17.2.1 Available cyanide consists of cyanide ion

(CN-), hydrogen cyanide in water (HCNaq) and

the cyano-complexes of zinc, copper, cadmium, mercury, nickel, and

silver.

17.2.2 Calibration blank--A 100 mL volume of reagent water

treated with the ligand-exchange reagents and analyzed using the FIA

procedure.

17.2.3 Calibration standard (CAL)--A solution prepared from the

dilution of stock standard solutions. A 100 mL aliquot of each of

the CALs are subjected to the analysis procedure. The resulting

observations are used to calibrate the instrument response with

respect to the analyte concentration.

17.2.4 Discharge--Specific discharge (also known as ``matrix

type'') means a sample medium with common characteristics across a

given industrial category or industrial subcategory. Examples

include: C-stage effluents from chlorine bleach mills in the Pulp,

Paper, and Paperboard industrial category; effluent from the

continuous casting subcategory of the Iron and Steel industrial

category; publicly owned treatment work (POTW) sludge; and in-

process streams in the Atlantic and Gulf Coast Hand-shucked Oyster

Processing subcategory. Specific discharge also means a discharge

with characteristics different from other discharges. Therefore, if

there are multiple discharges from a facility all with the same

characteristics, these are the same discharge for the purpose of

demonstrating equivalency of a method modification. In this context,

``characteristics'' means that results of the matrix spike and

matrix spike duplicate (MS/MSD) tests with the unmodified method

meet the QC acceptance criteria for recovery and relative percent

difference (RPD).

[[Page 36824]]

17.2.5 Initial precision and recovery (IPR)--Four aliquots of

the LRB spiked with the analytes of interest and used to establish

the ability to generate acceptable precision and accuracy. An IPR is

performed the first time this method is used and any time the method

or instrumentation is modified.

17.2.6 Laboratory control sample (LCS)--An aliquot of LRB to

which a quantity of mercury (II) cyanide stock solution is added in

the laboratory. The LCS is analyzed like a sample. Its purpose is to

determine whether the methodology is in control and whether the

laboratory is capable of making accurate and precise measurements.

17.2.7 Laboratory reagent blank (LRB)--An aliquot of reagent

water that is treated like a sample including exposure to all

glassware, equipment, and reagents that are used with other samples.

The LRB is used to determine if the method analyte or other

interferences are present in the laboratory environment, reagents,

or apparatus.

17.2.8 Matrix spike/matrix spike duplicate (MS/MSD)--An aliquot

of an environmental sample to which a quantity of the method analyte

is added in the laboratory. MS/MSDs are analyzed like a sample.

Their purpose is to determine whether the sample matrix contributes

bias to the analytical results. The background concentration of the

analyte in the sample matrix must be determined in a separate

aliquot and the measured values in the MS/MSD corrected for the

background concentration.

17.2.9 Minimum level (ML)--The level at which the entire

analytical system shall give a recognizable signal and acceptable

calibration point, taking into account method specific sample and

injection volumes.

17.2.10 Ongoing Precision and Recovery (OPR)--See Laboratory

control sample.

[FR Doc. 98-17963 Filed 7-6-98; 8:45 am]

BILLING CODE 6560-50-P