NEMI Method Summary

Method Summary Information

Method Number: I-6302 Media: SOILS/SEDIMENT
Revision: 1985
Method Source: U.S. Geological Survey (USGS)
Subcategory: INORGANIC Analytes in this method
Official Name: Cyanide, colorimetric, barbituric acid, automated-segmented flow
Descriptive Name Cyanide, recoverable-from-bottom-material, dry wt, colorimetric
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
80616 Byte file
Brief Method
Summary:
 This method is based on the chlorination of cyanide with chloramine-T and on the subsequent reaction with a pyridine-barbituric acid reagent (Goulden and others, 1972). This method detects simple cyanides only; therefore, any complex cyanides must first be broken down by passing the acidified sample solution through an ultraviolet digestion-distillation procedure. The distillation step also removes certain interferences.
Scope And
Application:
 This method may be used to determine cyanide in bottom material containing at least 0.5 mg/kg.
Applicable
Conc Range:
 at least 0.5 mg/kg
Interferences: Chloride interferes if its concentration exceeds 3,000 mg/L. Oxidizing agents may interfere. Glycine and urea at the 10-mg/L level do not interfere. A concentration of 10 mg/L sulfide increases the apparent cyanide concentration by approx 0.02 mg/L. Concentrations of sulfide greater than 10 mg/L interfere considerably. Thiocyanate is broken down to cyanide and sulfide by this procedure and, therefore, interferes on an equimolar basis. Sulfate concentrations of 4,000 mg/L do not interfere. Higher concentrations were not tested.
QC Requirements: Calibrate instrument using calibration standards (CAL). Quality control samples (QCS) and laboratory blanks (LB) analyzed at a minimum of I each after every 10 samples
Sample Handling: Container Description: 500 mL Polypropylene bottle, wide-mouth Treatment and Preservation: No treatment, preservation or special shipping requirements
Max Holding Time:
 180 days
 
Relative Cost: Less than $50
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