A Solid-Phase Extraction Based Soil Extraction Method for Pesticides of Varying Polarity
- H. J. Turin * and
- R. S. Bowman
Solid-phase extraction (SPE) is an innovative method for efficiently and quantitatively extracting pesticides from large numbers of soil samples. An extraction method using commercially available SPE columns has been developed and tested using three herbicides of varying polarity: bromacil [5-bromo-6-methyl-3-(1-methylpropyl)-2,4(1H,3H)pyrimidinedione], napropamide [N,N-diethyl-2-(1-naphthalenyloxy)propanamide], and prometryn [N,N′-bis(1-methylethyl)-6-(methylthio)-1,3,5-triazine-2,4-diamine]. The soil sample is shaken with a methanol/water mixture and centrifuged. The supernatant is then diluted with a concentrated NaCl solution, and drawn through an SPE column. The sorbed pesticides are finally eluted from the column with methanol. This method requires no specialized laboratory equipment and is well suited for processing large numbers of samples. Analyses of spiked soil samples show recoveries of over 90% and average coefficients of variation (CV's) ranging from 5% at high soil pesticide concentrations to 18% at lower concentrations. The practical detection limit for the method is approximately 10 µg/kg.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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