PROGRAMS AND PLANS--Quality control of pesticides analyses



                                         February 24, 1975

QUALITY OF WATER BRANCH TECNHNICAL MEMORANDUM NO. 75.14

Subject: PROGRAMS AND PLANS--Quality control of pesticides 
                             analyses

Recently, I appointed an ad hoc committee to review the 
current protocol used by our water-quality laboratories for 
confirmation of pesticide analyses and to recommend changes 
that might be appropriate on the basis of recent developments 
in analytical methodology, instrumentation, or practice of 
other laboratories. Section 8, page 29, TWRI Book 5, Chapter 
A3, has been revised on the basis of the committee's 
recommendations. The attached revised protocol will replace 
that originally published in the above manual, effective 
March 1, 1975, and will be implemented at all central 
laboratories as soon thereafter as possible. The revised 
protocol is in conformance with practices acceptable to
the Federal Working Group on Pest Managenent and represents a 
consensus of the principal Federal agencies involved in 
pesticide residue analysis, data evaluation, and pest 
management.  This same protocol will be used by the 
Environmental Protection Agency in analyzing samples 
collected by WRD personnel in the jointly operated National 
Pesticides Water Monitoring Program.



                               R. J. Pickering

Attachment

WRD Distribution: A, B, FO-LS,PO


8. Reporting and Confirmation

Pesticidc residues found in water samples are reported as 
follows: at conccntrations of less than 1.0 ug/l, two 
decimals and report less than 0.005 ug/l as 0.00 ug/l; at 
concentrations of 1.0 ug/l and greater, two significant 
figures. Pesticide residues in sediment and soil samples are 
reported as follows: less than 1.0 ug/kg to one decimal; 
1.0 ug/kg and greater, two significant figures. The 
identities of pesticide residues found in water or sediment 
must be supported by multiple-column gas chromatography. For 
data in question, or for concentrations of 1.0 ug/l or 
greater in water and of 10 ug/kg or greater in sediment, 
specific detection must be employed. Identities of compounds 
in concentrations of 2.0 ug/l or greater in water and of 
20 ug/kg or greater in sediment must be confirmed by mass 
spectrometry.