[Federal Register Volume 63, Number 129 (Tuesday, July 7, 1998)]
[Proposed Rules]
[Pages 36810-36824]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-17963]


      

[[Page 36809]]

_______________________________________________________________________

Part IV





Environmental Protection Agency





_______________________________________________________________________



40 CFR Part 136



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

Federal Register / Vol. 63, No. 129 / Tuesday, July 7, 1998 / 
Proposed Rules

[[Page 36810]]



ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 136

[FRL-6121-5]
RIN 2040-AC76


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

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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

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<SUP>-</SUP>). Cyanides are of the form 
A(CN)<INF>X</INF>, 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<SUP>-</SUP> and as 
hydrocyanic acid (HCN or hydrogen cyanide). The proportion of 
CN<SUP>-</SUP> 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<SUP>-</SUP>. 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<SUP>-</SUP>), 
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<INF>-</INF> 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)<INF>2</INF>), 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<SUP>-</SUP>), sulfide (S<SUP>2-</SUP>), carbonates 
(HCO<INF>3</INF><SUP>-</SUP>, CO<INF>3</INF><SUP>2-</SUP>), nitrite 
(NO<INF>2</INF><SUP>-</SUP>), oxidants (ClO<INF>4</INF><SUP>-</SUP>, 
O<INF>3</INF>, H<INF>2</INF>O<INF>2</INF>), bisulfite 
(HSO<INF>3</INF><SUP>-</SUP>), 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<SUP>-</SUP>) from weak and intermediate strength metallo-
cyanide complexes.
    In the flow-injection analysis system, a 200-<greek-m>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<SUP>-</SUP>). 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<SUP>-</SUP> 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 <greek-m>g/
L. The method detection limit (MDL; described at 40 CFR part 136, 
Appendix B) is 0.5 <greek-m>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 <greek-m>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)<INF>2</INF>) 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:
    <bullet> 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.
    <bullet> Analysis of a matrix spike (MS) and matrix spike duplicate 
(MSD) to demonstrate method accuracy and precision and to monitor 
matrix interferences. Hg(CN)<INF>2</INF> is the reference standard used 
for spiking.
    <bullet> Analysis of a laboratory blank to demonstrate freedom from 
contamination.
    <bullet> 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)<INF>2</INF> 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)<INF>2</INF> 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)<INF>2</INF> 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 <greek-m>g/L CN<SUP>-</SUP>.
    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 10<SUP>n</SUP>, where n is an integer. The ML for 
Method OIA-1677 was calculated to be 1.0 <greek-m>g/L CN<SUP>-</SUP>. 
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 <greek-m>g/L CN<SUP>-</SUP>. 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                                                                        
                                           EPA<SUP>1,35                  ed.                    ASTM                 USGS <SUP>2                   Other          
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                                        
                   *                  *                  *                  *                  *                  *                  *                  
24. Available Cyanide, mg/L         .....................  335.14500-CN G.......  D2036-91(B)            ....................  .........................
 Cyanide amenable to chlorination                                                                                                                       
 (CATC), Manual distillation with                                                                                                                       
 MgCl<INF>2 followed by titrimetry or                                                                                                                        
 spectrophotometry.                                                                                                                                     
Available, Flow injection and       .....................  .....................  .....................  ....................  OIA-1677.<SUP>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<SUP>-</SUP>), hydrogen cyanide in water 
(HCN<INF>aq</INF>), 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 <greek-m>g/L and 
the minimum level (ML) is 2.0 <greek-m>g/L. The dynamic range is 
approximately 2.0 <greek-m>g/L (ppb) to 5.0 mg/L (ppm) cyanide ion 
using a 200 <greek-m>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-
<greek-m>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 <greek-m>L 
samples.
    6.1.2  Gas diffusion manifold with a microporous 
Teflon<Register> 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, <gr-thn-eq>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 
AgNO<INF>3</INF> 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 AgNO<INF>3</INF> 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 
<greek-m>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 (<greek-m>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 <gr-thn-eq>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
D<INF>1</INF> = Concentration of cyanide in the spiked sample
D<INF>2</INF> = 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 (P<INF>a</INF>) and the standard deviation 
of the percent recovery (s<INF>p</INF>). Express the accuracy 
assessment as a percent recovery interval from P<INF>a</INF> - 
2s<INF>p</INF> to P<INF>a</INF> + 2s<INF>p</INF>. For example, if 
P<INF>a</INF> = 90% and s<INF>p</INF> = 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 (S<INF>r</INF>). Express the accuracy as a recovery 
interval from R - 2s<INF>r</INF> to R + 2s<INF>r</INF>. For example, 
if R = 95% and s<INF>r</INF> = 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 (<10% RSD), linearity through the origin can be 
assumed and the averaged calibration factor (area/concentration) can 
be used in place of a calibration curve.
    11.0  Procedure.
    This section describes the procedure for determination of 
available cyanide using the FIA system.
    11.1  Analysis of standards, samples, and blanks.
    11.1.1 Ligand-exchange reagent treatment of standards, samples, 
and blanks.
    11.1.2  To 100-mL of cyanide-containing sample (or standard or 
blank) at pH of approximately 12, add 100 <greek-m>L of ligand-
exchange reagent Part B (Section 7.10.5), 50 <greek-m>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 <5 mg/L, or as required by 
the permitting authority or permit.
    12.2.2  Blanks--Report results to three significant figures for 
cyanide concentrations found above the MDL (Section 1.3). Do not 
report results below the MDL unless required by the permitting 
authority or in the permit.
    13.0  Method Performance.
    13.1  Method detection limit (MDL)--MDLs from nine laboratories 
were pooled to develop the MDL of 0.5 <greek-m>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       <5.1% RSD
Ongoing precision and recovery                                          
 (Laboratory control sample)............          82-132             N/A
Calibration verification................          86-118             N/A
Matrix spike/matrix spike duplicate.....          82-130        <11% RPD
------------------------------------------------------------------------


 Table 2.--Species-Dependent Cyanide Recoveries Using Draft Method 1677 
                                   \1\                                  
------------------------------------------------------------------------
                                              0.20 <greek-  2.00 <greek-
                   Species                     m>g/mL CN<SUP>-    m>g/mL CN<SUP>- 
                                                                        
------------------------------------------------------------------------
[Zn(CN)<INF>4]<SUP>2-.................................    97.4 (0.7)    98.5 (0.7)
[Cd(CN)<INF>4]<SUP>2-.................................   100.0 (0.8)   100.0 (0.2)
[Cu(CN)<INF>4]<SUP>2-.................................   100.9 (1.3)    99.0 (0.6)
[Ag(CN)<INF>4]<SUP>3-.................................   101.8 (0.9)   100.0 (0.5)
[Ni(CN)<INF>4]<SUP>2-.................................   104.3 (0.2)   103.0 (0.5)
[Hg(CN)<INF>4]<SUP>2-.................................   100.0 (0.6)    99.0 (0.3)
Hg(CN)<INF>2.....................................   103.4 (0.4)    98.0 (0.3)
[Fe(CN)<INF>4]<SUP>4-.................................          0.0           0.0 
[Fe(CN)<INF>6]<SUP>3-.................................          0.0           0.0 
[Au(CN)<INF>2]<SUP>-..................................      \2\ 1.3               
                                                     (0.0)          0.0 
[Co(CN)<INF>6]<SUP>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 CN<SUP>1 concentration     recovery       % RSD   
----------------------------------------------------------------------------------------------------------------
Reagent water w/0.01M NaOH........  0 <greek-m>g/L          100 <greek-m>g/L as KCN..          108           4.0
POTW secondary effluent...........  3.0 <greek-m>g/L        100 <greek-m>g/L as KCN;           102           7.0
                                                             2 mg/L as [Pt(CN)<INF>6]<SUP>4-.                             
Petroleum Refinery Secondary        9.9 <greek-m>g/L        2 mg/L as KCN; 5 mg/L as            87          21  
 Effluent.                                                   [Fe(CN)<INF>6]<SUP>4-.                                       
Coke Plant Secondary Effluent.....  14.0 <greek-m>g/L       50 <greek-m>g/L as KCN...           95           4.0
Rolling Mill Direct Filter          4.0 <greek-m>g/L        None.....................           80          41  
 Effluent.                                                                                                      
Metals Finishing Indirect Primary   1.0 <greek-m>g/L        200 <greek-m>g/L as KCN;            92          16  
 Effluent.                                                   2 mg/L as KSCN.                                    
Reagent water w/0.01M NaOH........  0 <greek-m>g/L          200 <greek-m>g/L as KCN..          101           8.0
Reagent water w/0.01M NaOH........  0 <greek-m>g/L          10 mg/L as KCN; 10 mg/L            103           2.0
                                                             as [Pt(CN)<INF>6]<SUP>4-.                                    
Mining Tailing Pond Effluent......  842 <greek-m>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-minus>  plus or minus
<gr-thn-eq>  greater than or equal to
    17.1.2  Alphabetical characters.

g  gram
L  liter
mg  milligram
mg/L milligram per liter
<greek-m>g  microgram
<greek-m>g/L  microgram per liter
<greek-m>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<SUP>-</SUP>), hydrogen cyanide in water (HCN<INF>aq</INF>) 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