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Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory-Determination of pesticides in water by Carbopak-B solid-phase extraction and high-preformance liquid chromatography

Stephen L. Werner·Mark R. Burkhardt·Sabrina N. DeRusseau
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Abstract

In accordance with the needs of the National Water-Quality Assessment Program (NAWQA), the U.S. Geological Survey has developed and implemented a graphitized carbon-based solid-phase extraction and high-performance liquid chromatographic analytical method. The method is used to determine 41 pesticides and pesticide metabolites that are not readily amenable to gas chromatography or other high-temperature analytical techniques. Pesticides are extracted from filtered environmental water samples using a 0.5-gram graphitized carbon-based solid-phase cartridge, eluted from the cartridge into two analytical fractions, and analyzed using high-performance liquid chromatography with photodiode-array detection. The upper concentration limit is 1.6 micrograms per liter (=B5g/L) for most compounds. Single-operator method detection limits in organic-free water samples ranged from 0.006 to 0.032 =B5g/L= Recoveries in organic-free water samples ranged from 37 to 88 percent. Recoveries in ground- and surface-water samples ranged from 29 to 94 percent. An optional on-site extraction procedure allows for samples to be collected and processed at remote sites where it is difficult to ship samples to the laboratory within the recommended pre-extraction holding time of 7 days.

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Stephen L. Werner, Mark R. Burkhardt, Sabrina N. DeRusseau. 1996. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory-Determination of pesticides in water by Carbopak-B solid-phase extraction and high-preformance liquid chromatography. https://doi.org/10.3133/ofr96216

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