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United States Department of Agriculture

Agricultural Research Service

Title: Pesticide-Contaminated Soil Sample Stability During Frozen Storage

Authors
item Puchalski, M - MN DEPT OF AGRICULTURE
item Horvath, G - MN DEPT OF AGRICULTURE
item Loughran, M - MN DEPT OF AGRICULTURE
item Elsner, G - MN DEPT OF AGRICULTURE
item Koskinen, William

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 1, 1998
Publication Date: N/A

Interpretive Summary: Little information is available in the literature on stability of pesticide-contaminated soil samples during frozen storage prior to analysis. This research was conducted to evaluate the effects of sample holding times on frozen clay loam, clay and loamy sand soils contaminated with seven different herbicides: EPTC, trifluralin, alachlor, dicamba, 2,4- -D, silvex, and 2,4,5-TB. Each soil was spiked with normal use levels of seven herbicides (1 ppm each herbicide) and stored at 5 degrees F for up to 450 days. The soils tested could be stored up to 180 days without affecting pesticide recovery. Clay loam and loamy sand soils could be stored up to 270 days without affecting recovery. Trifluralin showed the greatest decrease in concentration over the length of the study in all three soil categories with the largest loss (60 percent) in the clay soil. These data are important to anyone conducting pesticide analyses in soil, including research scientists and regulatory agencies. This study shows that long- term frozen storage can affect the sample integrity of some pesticide- contaminated soils. In addition, soil type can be a factor in soil integrity during frozen storage. Spiked controls should be part of quality assurance and quality control during long term frozen storage.

Technical Abstract: Little information is available in the literature on stability of pesticide-contaminated soil samples during frozen storage prior to analysis. This research was conducted to evaluate the effects of sample holding times on frozen clay loam, clay and loamy sand soils contaminated with seven different herbicides: EPTC, trifluralin, alachlor, dicamba, 2,4- -D, silvex, and 2,4,5-TB. Each soil was spiked with normal use levels of seven herbicides (1 ppm each herbicide) and stored at 5 degrees F for up to 450 days. The soils tested could be stored up to 180 days without affecting pesticide recovery. Clay loam and loamy sand soils could be stored up to 270 days without affecting recovery. Trifluralin showed the greatest decrease in concentration over the length of the study in all three soil categories with the largest loss (60 percent) in the clay soil. These data are important to anyone conducting pesticide analyses in soil, including research scientists and regulatory agencies. This study shows that long- term frozen storage can affect the sample integrity of some pesticide- contaminated soils. In addition, soil type can be a factor in soil integrity during frozen storage. Spiked controls should be part of quality assurance and quality control during long term frozen storage.

Last Modified: 12/20/2014