ASTM D5049-23

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D5049 − 23
Standard Practice for
Screening of Cyanides in Waste
This standard is issued under the fixed designation D5049; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D2036 Test Methods for Cyanides in Water
D5681 Terminology for Waste and Waste Management
1.1 This practice is applicable to the screening of cyanides
D6696 Guide for Understanding Cyanide Species
in waste liquids, sludges, semisolids, and solids. The following
D7365 Practice for Sampling, Preservation and Mitigating
screening methods are included:
Interferences in Water Samples for Analysis of Cyanide
Sections
D8273 Practice for Determination of Total and Available
Method A—Chloramine T 13 – 15
Method B—Prussian Blue 16 – 18 Cyanide in Solid Waste and Soil after Alkaline Extraction
Method C—Cyanide Test Paper 19 – 21
E200 Practice for Preparation, Standardization, and Storage
Method D—Gas Detector Tube 22 – 26
of Standard and Reagent Solutions for Chemical Analysis
Method E—Ion Selective Electrode 27 – 31
2.2 Code of Federal Regulations:
1.2 This practice is designed and intended as a compilation
21 CFR Part 1308 Schedules of Controlled Substances
of screening tests to complement more sophisticated quantita-
tive analytical techniques that may be used to determine
3. Terminology
cyanide concentration. This practice provides the user the
option and the ability to “screen” waste for potentially hazard-
3.1 See Terminology D5681 for definitions of terms related
ous levels of cyanide when the more sophisticated techniques
to waste and waste management.
are not available and the total waste composition is unknown.
3.2 See Guide D6696 for terminology specific to the various
1.3 The values stated in SI units are to be regarded as the
forms of cyanide.
standard.
3.3 Definitions of Terms Specific to This Standard:
1.4 This standard does not purport to address all of the
3.3.1 screening method—a preliminary, qualitative, or semi-
safety concerns, if any, associated with its use. It is the
quantitative test, developed from classical qualitative and
responsibility of the user of this standard to establish appro-
quantitative techniques, that is designed to efficiently give the
priate safety, health, and environmental practices and deter-
user specific information about a waste that will aid in
mine the applicability of regulatory limitations prior to use.
determining waste identification, process compatibility, and
Specific hazard information is given in Section 8 and 18.5.
safety in handling.
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
4. Summary of Screening Methods
ization established in the Decision on Principles for the
4.1 Method A, Chloramine-T Method—The presence of
Development of International Standards, Guides and Recom-
cyanides can be observed when cyanides react with
mendations issued by the World Trade Organization Technical
chloramine-T reagent at pH 8 to form cyanogen chloride. The
Barriers to Trade (TBT) Committee.
addition of barbituric acid to cyanogen chloride gives intensive
2. Referenced Documents
red color. This method indicates cyanides amenable to chlori-
nation.
2.1 ASTM Standards:
D1193 Specification for Reagent Water
4.2 Method B, Prussian Blue Method—The pH of a sample
is adjusted to pH 12 with NaOH and subsequently, solutions of
ferrous sulfate and ferric chloride are added. By the addition of
This practice is under the jurisdiction of ASTM Committee D34 on Waste
Management and is the direct responsibility of D34.01 on Monitoring and
concentrated sulfuric acid in the presence of cyanides, a deep
Characterization.
blue color (Prussian blue) is produced. This method indicates
Current edition approved Nov. 1, 2023. Published November 2023. Originally
the presence of free cyanide and many complex cyanides.
approved in 1990. Last previous edition approved in 1990 as D5049 – 90, which
was withdrawn in 1999 and reinstated November 2023. DOI: 10.1520/D5049-23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Code of Federal Regulations available from the Superintendent of Documents,
the ASTM website. United States Government Printing Office, Washington, DC 20402.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5049 − 23
4.3 Method C, Cyanide Test Paper Method—A portion of such specifications are available. Other grades may be used,
the sample is acidified in a flask or test tube releasing hydrogen provided it is first ascertained that the reagent is of sufficiently
high purity to permit its use without lessening the accuracy of
cyanide gas from cyanides. The presence of hydrogen cyanide
the determination (see Practice E200).
gas is indicated by a color change in the cyanide screening
paper that is held just above the solution. This method indicates
7.2 Purity of Water—Unless otherwise indicated, references
dissociable cyanide that could readily evolve hydrogen cyanide
to water shall be understood to mean reagent water as defined
gas.
by Type I, II, or III in Specification D1193.
4.4 Method D, Gas Detector Tube Method—A portion of the 7.3 Sodium Hydroxide (2.5 N)—Dissolve 100 g sodium
hydroxide (NaOH) in water and dilute to 1 L in a volumetric
sample is acidified in a beaker to release cyanide as hydrogen
flask.
cyanide gas. The gas is funneled through a detector tube,
creating a color stain in the tube in proportion to the concen-
7.4 Cyanide Solution, Standard (50 mg/L)—Dilute 0.125 g
tration of cyanide gas in the vapor. A definite color change in
potassium cyanide (KCN) with NaOH solution to 1 L in a
the detector tube indicates the presence of cyanide. This
volumetric flask.
method indicates dissociable cyanide that could readily evolve
8. Hazards
hydrogen cyanide gas.
NOTE 1—Methods B, C, and D are designed to release highly toxic
4.5 Method E, Ion Selective Electrode—The pH of a portion hydrogen cyanide vapors by means of acidification of alkaline materials.
All tests must be performed under a laboratory fume hood. In addition,
of the sample is adjusted to pH >11 with NaOH. When the
sufficient personal protective equipment (PPE) must be worn to protect the
sensing element of the ion selective electrode is in contact with
analyst from inhalation, corrosive materials, and violent reactions.
a solution containing cyanide ions, an electrode potential
8.1 Avoid inhalation and skin or eye contact with all
develops which corresponds to the cyanide concentration. This
hazardous wastes.
method will indicate the presence of free cyanide and weak
cyanide complexes with metals which could readily evolve
9. Sample Collection, Preservation, and Handling
hydrogen cyanide gas. The method is suitable for waste liquids,
9.1 Samples should be analyzed as soon as possible. Liquid
sludges, semisolids, and solids and is the safest among these
samples can be preserved for up to 14 days by using 2.5 N
listed screening methods because the high pH virtually elimi-
NaOH to adjust the pH of the sample to a range between 10 to
nates the potential of operator exposure to HCN.
12.
9.2 Test Methods D2036 and Practice D7365 provide infor-
5. Significance and Use
mation on additional preservation techniques and elimination
5.1 This compilation of methods is intended for use by those
of potential interferences.
in the waste management and related industries to determine
10. Report
the presence of cyanides.
10.1 The report shall include the following information:
6. Interferences
10.1.1 Sample identification,
10.1.2 Sample source,
6.1 Common interferences include oxidizing agents,
10.1.3 Sampling procedure,
sulfides, aldehydes, glucose and other sugars, high concentra-
10.1.4 Date of test,
tion of carbonate, fatty acids, thiocyanate, and other sulfur
10.1.5 Sample classification: positive or negative, and
containing compounds. Each of these interferences and the
10.1.6 Reference to the analytic procedure used.
extent to which they interfere is dependent upon the technique
used. Sulfide and other reduced sulfur containing compounds,
11. Quality Control
aldehydes, and oxidizing agents interfere with all methods by
11.1 Method/reagent blanks, duplicates, fortification
reacting with CN in the sample reducing its concentration. An
(spikes) samples (where applicable), and quality control check
exception is thiocyanate, which may form in the presence of
samples of appropriate matrices should be performed at an
cyanide and sulfur compounds present in the sample, resulting
action level specified and documented by the laboratory at an
in a false positive by Methods A and C.
appropriate frequency.
6.2 It is beyond the scope of these methods to describe
11.2 Suitability of this compilation of tests should be
procedures for overcoming all of the possible interferences that determined by each laboratory using appropriate standards for
may be encountered. Practice D7365 can be referenced for
the action level and the matrix of concern.
interferences and their possible elimination.
11.3 A standard shall be run with each batch of samples.
7. Reagents and Materials
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
7.1 Purity of Reagents—Reagent grade chemicals shall be
listed by the American Chemical Society, see Analar Standards for Laboratory
used in all tests. Unless otherwise indicated, it is intended that
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
all reagents conform to the specifications of the Committee on
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
Analytical Reagents of the American Chemical Society where MD.
D5049 − 23
12. Precision and Bias 15.6 Add four drops of pyridine-barbituric acid reagent and
mix again.
12.1 No statement is made about either the precision or bias
of this practice since the result merely states whether there is
15.7 Observe color change. Presence of cyanides is indi-
conformance to the criteria for success specified in the proce-
cated by red color.
dure.
Screening Method B—Prussian Blue
Screening Method A—Chloramine T
16. Interferences
13. Interferences
16.1 See Practice D7365 for listings of cyanide test meth-
13.1 The presence of formaldehyde interferes with this
ods.
screening method.
16.2 Samples containing copper or nickel or having blue or
13.2 The presence of high levels of reducing agents inter-
green color may show positive interferences. These samples
feres with this screening method.
should be analyzed for available or total cyanide using one of
−
13.3 Thiocyanate (SCN ) reacts with chloramine-T, creat-
the methods listed in Practice D7365.
ing a positive interference.
16.3 Solid samples suspected of containing high concentra-
14. Reagents and Materials
tions of cyanide, Prussian Blue, or other metal-metal cyanide
complexes should be extracted using Practice D8273.
14.1 Chloramine-T (100 g/L)—Dissolve 1 g chloramine-T
in 10 mL water.
17. Reagents and Materials
14.2 Sodium Hydroxide, Standard Solution (0.1 M)—
17.1 Sodium Hydroxide (2.5 N)—Dissolve 100 g sodium
Dissolve 4.0 g sodium hydroxide (NaOH) in water and dilute
hydroxide (NaOH) in water and dilute to 1 L in a volumetric
to 1 L in a volumetric flask.
flask.
14.3 Potassium Dihydrogen Phosphate (0.1 M)—Dissolve
13.6 g potassium dihydrogen phosphate (KH PO ) in water
17.2 Ferrous Sulfate Heptahydrate (100 g/L)—Dissolve
2 4
and dilute to 1 L in a volumetric flask.
100 g of ferrous sulfate heptahydrate (FeSO ·7H O) in water
4 2
and dilute to 1 L in a volumetric flask. Preserve the solution by
14.4 Phosphate Buffer pH 8—Mix 46.1 mL 0.1 M NaOH
adjusting the pH to 2 with concentrated sulfuric acid (H SO ).
2 4
and 50 mL of 0.1 M KH PO .
2 4
17.3 Ferric Chloride Hexahydrate (50 g/L)—Dissolve 50 g
14.5 Pyridine-Barbituric Acid Solution—Mix 1.5 g barbitu-
of ferric chloride hexahydrate (FeCl ·6H O) in water and dilute
ric acid with 5 mL of water. Add 7.5 mL of pyridine. Add
3 2
to 1 L in a volumetric flask.
1.5 mL of concentrated hydrochloric acid (HCl) and dilute to
25 mL with water. The solution will completely dissolve upon
17.4 Sulfuric acid (concentrated H SO ).
2 4
dilution with water.
17.5 Glass bottle or jar.
NOTE 2—Barbituric acid is classified as a Schedule III drug by the U.S.
Department of Justice, Drug Enforcement Administration, Diversion 17.6 pH indicator strip with a range of 0 to 14.
Control Division. This reagent requires locked storage and record
keeping.
18. Procedure
14.6 White ceramic spot plate or disposable beaker.
18.1 Place approximately 1 to 5 g of sample into beaker.
14.7 Stirring rod.
18.2 Adjust pH to 12 to 13 by the addition of 2.5 N NaOH
14.8 Disposable transfer pipettes.
(5 to 10 mL may be required). Slurry solid samples by adding
14.9 pH indicator strip, with a range of 0 to 14.
approximately 1 + 10 water solution before checking pH.
Check with pH paper.
15. Procedure
18.3 Add 5 to 10 mL FeSO (100 g/L) solution and mix.
15.1 Slurry solid samples (1 + 10) with water.
18.4 Add 5 to 10 mL of FeCl ·6H O (50 g/L) and mix.
3 2
15.2 Place 0.25 mL (approximately five drops) of sample or
extract from solid slurry in cavity of a spot plate or in a
18.5 Add the concentrated sulfuric acid slowly to adjust the
disposable beaker.
pH below 1.0 (check with pH indicator paper).
15.3 Add one drop of phosphate buffer and mix.
NOTE 3—Mixing concentrated sulfuric acid with an alkaline solution
can result in a violent reaction with the generation of heat. In addition,
15.4 Check the pH with indicator paper and continue drop
hydrogen cyanide vapors are generated upon acidification of alkaline
by drop the addition of buffer solution until pH 8 is obtained.
materials containing cyanides. All tests must be performed under a
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