NEMI Method Summary

Method Summary Information

Method Number: I-3300 Media: WATER
Revision: 1985
Method Source: U.S. Geological Survey (USGS)
Subcategory: INORGANIC Analytes in this method
Official Name: Total Cyanide in Water by Colorimetry with Pyridine-Pyrazolone
Descriptive Name Cyanide in Water by Colorimetry
Source Info: USGS Branch of Information Services
Box 25286, MS 417
Federal Center
Denver, CO 80225-0286
Phone: 303-202-4700
Citation: USGS Methods, Volume A1
37399 Byte file
Brief Method
Summary:
 This method is based on the chlorination of cyanide and the subsequent reaction of the product with a mixed solution of pyridine-pyrazolone to form a stable complex dye. The method detects only simple cyanides; therefore, any complex cyanides present must be broken down. The decomposition of complex cyanides is accomplished by an acid reflux and distillation prior to the colorimetric procedure. The distillation also removes certain interferences from water samples.
Scope And
Application:
 The method covers the determination of cyanide in water and water-suspended sediment containing at least 0.01 mg/L of cyanide. The test method may be used to determine cyanide in bottom material containing at least 0.5 mg/kg. Total cyanide in water-suspended sediment may be determined if each sample is shaken vigorously and a suitable aliquot of well mixed sample withdrawn.
Applicable
Conc Range:
 0.01 mg/L - * (* Method does not specify an upper detection limit.)
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: Calibrate instrument using calibration standards (CAL); quality control samples (QCS); and laboratory blanks (LB) analyzed at a minimum of 1 for every 10 samples.
Sample Handling: Container Description: 250 mL Polyethylene bottle.
Treatment and Preservation: use unfiltered sample to rinse bottles; then add NaOH to pH>12 to collected sample, chill and maintain at 4 deg C; ship immediately.
Max Holding Time:
 180 days
 
Relative Cost: Less than $50
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