NEMI Method Summary

Method Summary Information

Method Number: 335.2 Media: WATER
Revision: Issued 1974; Editorial Revision 1974 & 1978; Technical Revision 1980
Method Source: U.S. EPA National Exposure Research Laboratory (NERL) [formerly EMSL]
Analytes in this method
Subcategory: INORGANIC
Official Name: Cyanide, Total (Titrimetric; Spectrophotometric)
Descriptive Name Total Cyanide in Water
Source Info: U.S.EPA National Exposure Research Laboratory (NERL)
Microbiological and Chemical Exposure Assessment Research Division (MCEARD)
[formerly the Environmental Monitoring Systems Laboratory (EMSL), Cincinnati, OH]
26 West Martin Luther King Drive
Cincinnati, Ohio 45268-0001
Fax: 513-569-7757
email: DWmethods.help@epa.gov
Citation: Methods for the Chemical Analysis of Water and Wastes (MCAWW) (EPA/600/4-79/020)
96379 Byte file
Brief Method
Summary:
 The cyanide as hydrocyanic acid (HCN) is released from cyanide complexes by means of a reflux-distillation operation and absorbed in a scrubber containing sodium hydroxide solution. The cyanide ion in the absorbing solution is then determined by volumetric titration using silver nitrate or colorimetrically using pyridine-barbituric acid procedure.
Scope And
Application:
 This method is applicable to the determination of cyanide in drinking, surface and saline waters; and domestic and industrial wastes.
Applicable
Conc Range:
 0.02 - 1 mg/L
Interferences: (1) Oxidizing agents can destroy cyanides during storage.
(2) Sulfide can complex with cyanide in sample or distillate.
(3) Fatty acids cause interference during distillation.
(4) Carbonate causes interference during distillation.
(5) Aldehydes cause interference during distillation.
(6) Glucose/Sugars cause interference during distillation.
(7) Sulfur-containing compound causes interference during distillation by forming free sulfide that is captured in distillate.
QC Requirements: not included
Sample Handling: Collect at least 1 L samples in glass or plastic bottles. Test sample for the presence of oxidizing agents using KI-starch paper. If oxidizers are detected, add ascorbic acid until a drop test is negative. Then add 0.06 g of additional ascorbic acid. Preserve samples by adjusting to a pH > 12 with NaOH. Refrigerate samples at 4 degrees C until analysis. Analyze samples as soon as possible.
Max Holding Time:
 14 days.
 
Relative Cost: Less than $50
4700
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