NEMI Method Summary

Method Summary Information

Method Number: 245.2 Media: WATER
Revision: Issued 1974
Method Source: U.S. EPA National Exposure Research Laboratory (NERL) [formerly EMSL]
Analytes in this method
Subcategory: INORGANIC
Official Name: Mercury (Automated Cold Vapor Technique)
Descriptive Name Mercury by CVAA (Automated)
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)
56412 Byte file
Brief Method
Summary:
 Inorganic mercury in a sample is reduced to the elemental state (using SnSO4 or SnCl2) and aerated from solution. The mercury vapor passes through a cell positioned in the light path of a cold vapor atomic absorption (CVAA) spectrophotometer. The concentration of mercury is measured using the CVAA spectrophotometer. To detect total mercury (inorganic and organic mercury), the sample is treated with potassium permanganate and potassium persulfate to oxidize organic mercury compounds. After oxidation, the samples are analyzed as inorganic mercury.
Scope And
Application:
 This method determines mercury in surface waters and in certain saline waters, wastewaters, effluents, and domestic sewages. Inorganic mercury or total mercury can be determined.
Applicable
Conc Range:
 0.2 -20.0 ug/L
Interferences:

(A) Ions and metals: Sulfide, chloride, copper, and tellurium are reported interferences.

(B) Volatile organic materials: Certain volatile organic compounds which absorb in the range of mercury are reported interferences. A preliminary run under oxidizing conditions, without stannous sulfate, would determine if certain volatile organic materials are present.

(C) Interferences: All interferences can be overcome by use of the Manual Mercury Method.

(D) Contamination: Avoid contact with materials that may contain mercury (e.g., glassware that was in contact with a mercury reagent).
QC Requirements: Not Provided
Sample Handling: Preserve samples to pH < 2 with nitric acid upon collection. If dissolved mercury is desired, filter the sample.
Max Holding Time:
 Not Provided
 
Relative Cost: $51 to $200
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