NEMI Method Summary

Method Summary Information

Method Number: 218.3 Media: WATER
Revision: Issued 1978
Method Source: U.S. EPA National Exposure Research Laboratory (NERL) [formerly EMSL]
Analytes in this method
Subcategory: INORGANIC
Official Name: Chromium (Atomic Absorption, Chelation-Extraction)
Descriptive Name Chromium by Chelation Extraction and Flame AA
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)
15785 Byte file
Brief Method
Summary:
 This method is based on the chelation extraction of hexavalent chromium with ammonium pyrrolidine dithiocarbamate (APDC) following oxidation of trivalent chromium. The chelate is extracted with methyl isobutyl ketone (MIBK) and is analyzed using a flame atomic absorption spectrometer. Specifications for instrument operation and preparation of standards are provided.
An alternative extraction is also described in EPA Method 200.0, Section 9.2, which uses pyrrolidine dithiocarbamic acid in chloroform.
Scope And
Application:
 This method determines total chromium in drinking, surface and saline waters, and certain domestic and industrial wastes (provided that no interferences are present).
Applicable
Conc Range:
 1-25 ug/L.
Interferences: Reactive Metals: High concentrations of other reactive metals, as may be found in wastewaters, may interfere (but not at levels normally found in fresh water).
For additional interferences see EPA Method 200.0.
QC Requirements: QC requirements for drinking water procedures are provided in method 200.0
Sample Handling: Sample handling and preservation procedures are provided in EPA Method 200.0.
Max Holding Time:
 6 months (MCAWW, Table 1).
Sample Prep Met 200.0
Relative Cost: Less than $50
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