A Novel Simple Pretreatment Approach for Fast Determination of Multi-residue Pesticides in Aqueous Samples

Abstract

In this study, a simple and efficient pretreatment method to extract multi-class, multi-residue pesticides in water is developed. Based on high sensitivity and selectivity analytical instruments have been developed, large scale water sample is no longer to be needed for pretreatment and the solvent for extraction can be reduced. The method in the study combines two steps: A modified LLE process for less polar pesticides and solid supported liquid extraction (SLE) for more polar ones. The result shows that the mean recovery of each pesticide in three or four replicates of quality control and matrix spike samples is mostly good range from 70 to 140 % with relative standard deviations ranging from 2 to 25 %. It is worth to note that the venting during extraction process is important due to the high vapor pressure of DCM; poor venting will cause the sample spurt and lower analytes recovery and raise the deviation between samples. The method established in the study conjugates a simple pretreatment procedure and high sensitivity and selectivity detection system. It is adapted to quantify and qualify the trace pesticides in water, and also provided as a monitoring tool for the distribution and environmental fate of pesticides.