NEMI Method Summary

Method Summary Information

Method Number: 547 Media: WATER
Revision: July 1990
Method Source: U.S. EPA National Exposure Research Laboratory (NERL) [formerly EMSL]
Analytes in this method
Subcategory: ORGANIC
Official Name: Determination of Glyphosate in Drinking Water by Direct-Aqueous-Injection HPLC, Post Column Derivitization, and Fluorescence Detection
Descriptive Name Glyphosate in Water Using HPLC w/ Post Column Derivitization
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 Determination of Organic Compounds in Drinking Water - Supplement II (EPA/600/R-92-129)
64855 Byte file
Brief Method
Summary:
 An aliquot of a filtered water sample is injected into a cation exchange high performance liquid chromatography (HPLC) column. Separation is achieved by using an isocratic elution. After elution from the analytical column, the analyte is oxidized with calcium hypochlorite. The product (glycine) is then coupled with o-phthalaldehyde-2-mercaptoethanol complex at 38oC to give a derivative fluorophor (post-column derivitization). The concentration of glyphosate eluted from the HPLC column is measured by detecting the fluorescence of the derivative with a fluorometer.
Scope And
Application:
 This method determines glyphosate in drinking water.
Applicable
Conc Range:
 Not specified in method. Range differs depending on matrix and instrumentation.
Interferences:

(A) Glassware contamination: Thoroughly clean glassware, including baking or solvent rinse.

(B) Reagent contamination: Use high purity reagents.
QC Requirements:

Initial demonstration of laboratory capability, followed by analysis of laboratory reagent blanks (LRBs), laboratory fortified matrix samples, laboratory fortified blanks (LFBs), and QC samples. Initial demonstration of laboratory capability includes analysis of LFBs at an analyte concentration of 250 ug/L. A MDL also must be determined.
Sample Handling:

Collect samples in glass containers following conventional sampling practices. Dechlorinate samples with 100 mg/L of sodium thiosulfate. Store samples at 4oC away from light until analysis.
Max Holding Time:

14 days generally; up to 18 months for glyphosate in frozen samples.
 
Relative Cost: $201 to $400
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