Approval of a Water Quality Analytical Method for the Determination of Moderate Use Pesticides and Degradates by the National Water Quality Laboratory 
                        
                    March 23, 2001 

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 a Water Quality Analytical Method for the 
Determination of Moderate Use Pesticides and Degradates by the National 
Water Quality Laboratory 

The Office of Water Quality (OWQ) has approved a new Water Quality 
Analytical Method for the determination of moderate use pesticides and 
degradates in filtered water developed by the National Water Quality 
Laboratory (NWQL).  This new method is designed to complement the existing 
NWQL method O-1126-95, known as Schedule 2001 (laboratory extraction) and 
Schedule 2010 (field extraction) as described in Zaugg, et.al., Open File 
Report 95-181, available at:   

http://wwwnwql.cr.usgs.gov/Public/pubs/OFR95-181/OFR_95-181.html.  The new 
method uses the same solid-phase extraction procedure and the same gas 
chromatography/mass spectrometry (GC/MS) determination procedure as the 
existing method.  The new method determines 41 parent pesticides and 
degradates in filtered water plus 35 additional parent pesticides and 
degradates which have greater bias and variability, or shorter holding 
times, than the other compounds.  These additional compounds will be 
reported with the 'E' data qualifier signaling their greater quantitative 
uncertainty.  The new method number is O-2002-01 and can be requested 
through the NWQL as Schedule 2002 (laboratory extraction) or Schedule 2011 
(field extraction).  Field matrix spike mixtures for this method are not 
yet available, so for quality control sample information, please contact 
Mike Schroeder or Mark Sandstrom at the NWQL (see below).   

This method approval process follows the technical procedure specified in 
OWQ Tech Memo 98.05, except that this method is described in a Water 
Resources Investigations Report instead of an Open File Report.  The 
method performance of the 41 parent pesticides and degradates, along with 
the additional E-qualified 35 parent pesticides and degradates, is 
described in:   

Methods of Analysis by the U.S. Geological Survey National Water Quality 
laboratory – Determination of Moderate-Use Pesticides and Selected 
Degradates in Water by C-18 Solid-Phase Extraction and Gas 
Chromatography/Mass Spectrometry, by Mark W. Sandstrom, Max E. Stroppel, 
William T. Foreman, and Michael P. Schroeder.  U.S. Geological Survey 
Water Resources Investigations Report 01-XXXX (number to be assigned upon 
Director's approval).   

When approved, the report will be available through the NWQL web site at:  
http://wwwnwql.cr.usgs.gov/USGS/Pubs/pubs.html.   

The complete list of parent pesticides and degradates is available through 
the NWQL web site http://wwwnwql.cr.usgs.gov/USGS.  Please click on SPiN 
and request Schedule 2002.   

If you have questions about the new analytical method or would like a copy 
of the report, when it is available, please contact Mark Sandstrom 
(sandstro@usgs.gov, (303) 236-3943) or Mike Schroeder (schroede@usgs.gov, 
(303) 236-3270) at the NWQL.   

If you have questions about the method approval process, please contact 
Pete Rogerson (rogerson@usgs.gov, (303) 236-1836).