NEMI Method Summary

Method Summary Information

Method Number: 991.08 Media: WATER
Revision: Final Action - 1993
Method Source: AOAC International
Subcategory: ORGANIC Analytes in this method
Official Name: Glyphosate and Aminomethylphosphonic Acid (AMPA) in Environmental Water by Liquid Chromatographic Method
Descriptive Name Glyphosate and AMPA in Environmental Water
Source Info: AOAC International
481 North Frederick Avenue
Suite 500
Gaithersburg, Maryland 20877-2417 USA
Phone: 1-301-924-7077 (worldwide), or 1-800-379-2622 (toll-free from North America)
Fax: 1-301-924-7089
E-mail: aoac@aoac.org
Citation: AOAC Methods Volume 1, 16th Ed. (1998)
 
Brief Method
Summary:
 Environmental water containing glyphosate and aminomethylphosphonic acid (AMPA) is evaporated to dryness using a rotary evaporator and the residue is dissolved in EDTA solution. Glyphosate and AMPA are separated and detected by liquid chromatography using a postcolumn reaction specific for primary amines. Glyphosate is oxidized in a postcolumn reactor coil at 50 degrees C with calcium hypochlorite to form glycine. Glycine is reacted with o-phthalaldehyde (OPA) in the presence of mercaptoethanol (MERC) in a second coil to form a fluorophor, which is detected fluorometrically (excitation 340 nm, emission 425-455 nm). AMPA is relatively unreactive toward calcium hypochlorite but undergoes a similar reaction with OPA-MERC reagent to form another fluorophor, which is detected fluorometrically under same conditions as for glycine.
Scope And
Application:
 Applicable to determination of glyphosate and AMPA in ground water, drinking water, and surface water at 0.5-5000 ug/L.
Applicable
Conc Range:
 0.5 - 5000ug/L
Interferences: Method interferences caused by contaminants in solvents, reagents, glassware, and other sample-processing hardware that lead to discrete artifacts and/or elevated base lines in chromatograms.
QC Requirements: IDMP, MB, SS, CV (every 2 samples)
Sample Handling: Samples should be frozen as soon as possible after collection.
Max Holding Time:
 
Relative Cost: $201 to $400
URL to obtain ordering information for this method:
http://www.aoac.org/pubs/oma.htm
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