May 1, 2000

To:     Water Resources Division

From:   Peter F. Rogerson, Senior Chemist
        Office of Water Quality

For:    LeRoy Schroder, Chief
        Branch of Quality Systems

Subject:  Approval of  Water Quality Analytical Methods for the
Determination of Chloroacetanilide Herbicide Metabolites in Water Using
High Performance Liquid Chromatography - Diode Array Detection and High
Performance Liquid Chromatography -  Mass Spectrometry

The Office of Water Quality (OWQ) has approved two new water-quality
analytical methods by the U.S. Geological Survey (USGS) Organic Chemistry
Research Group, Lawrence, Kansas for the determination of
chloroacetanilide herbicide metabolites in water by solid-phase extraction
and high performance liquid chromatography - diode array detection (HPAA)
and high performance liquid chromatography - mass spectrometry (LCAA).
This water-quality analytical methods approval follows the technical
procedure specified in OWQ Tech Memo 98.05.  The Open File Report (OFR) is
entitled:

Methods of Analysis by the U.S. Geological Survey Organic Geochemistry
Research Group - Determination of Chloroacetanilide Herbicide Metabolites
in Water Using High-Performance Liquid Chromatography-Diode Array
Detection and High-Performance Liquid Chromatography/Mass Spectrometry, by
L. R. Zimmerman, K.A. Hostetler, and E. M. Thurman.  U.S. Geological
Survey OFR 00-182.

Both methods determine 6 chloroacetanilide herbicide metabolites in
samples of filtered water.  Method reporting limits for HPAA are 0.2
micrograms per liter (ug/L), while reporting limits for LCAA are 0.05
ug/L.

The following list of National Water Information System (NWIS) Parameter
Codes and Method Codes have been established for water concentration data
from these methods:

Method HPAA (US Geological Survey (USGS) Method Number O-2133-00)
Parameter       Method  Analyte
Code    Code    Name
61029   W       Acetochlor ethane sulfonic acid, water, filtered, ug/L
61030   W       Acetochlor oxanilic acid, water, filtered, ug/L
50009   W       Alachlor ethane sulfonic acid, water, filtered, ug/L
61031   W       Alachlor oxanilic acid, water, filtered, ug/L
61043   W       Metolachlor ethane sulfonic acid, water, filtered, ug/L
61044   W       Metolachlor oxanilic acid, water, filtered, ug/L

Method LCAA (US Geological Survey (USGS) Method Number O-2134-00)
Parameter       Method Analyte
Code    Code    Name
61029   X       Acetochlor ethane sulfonic acid, water, filtered, ug/L
61030   X       Acetochlor oxanilic acid, water, filtered, ug/L
50009   X       Alachlor ethane sulfonic acid, water, filtered, ug/L
61031   X       Alachlor oxanilic acid, water, filtered, ug/L
61043   X       Metolachlor ethane sulfonic acid, water, filtered, ug/L
61044   X       Metolachlor oxanilic acid, water, filtered, ug/L

The fixed value for the analyzing agency (parameter code 00028) is:  82013
 (District Research Water-Quality lab, Lawrence, KS.)

If you would like a copy of the report, please contact Betty Scribner 
(scribner@usgs.gov) (785) 832-3564.  If you have questions about the 
method approval process, please contact Pete Rogerson (rogerson@usgs.gov) (303) 236-1836.