Determination of Triazine Pesticides in Water Samples by Capillary Electrophoresis Coupled with Solid Phase Extraction Based on Magnetic Graphene Nanocomposite

In this study, magnetic solid. phase extraction (MSPE) combined with capillary electrophoresis was developed for the simultaneous determination of four triazine pesticides in aqueous solution. The obtained magnetic nanocomposite (graphene/Fe3O4, G/Fe3O4) as adsorbent for MSPE endowed the method with good enrichment for triazine pesticides. The MSPE conditions such as pH of sample solution, amount of adsorbent, extraction time and elutent were investigated. Under the optimal MSPE conditions including 20 mg of adsorbent (G/Fe3O4), 0.5 mL of acetone as eluent and 20 min of extraction time in pH 7.0 solution, good linearities were obtained for the analytes between peak area and concentration in the range of 5-500 mu g/L with correlation coefficients greater than 0.9909. Detection limits were less than 3.12 mu g/L. The relative standard deviations (RSDs) for both intra. and inter. day analysis (n = 5) were in the range of 2.7% - 12.7% and 7.7% - 14.0%, respectively. The established method was applied to analyze the water samples (river water and tap water), and the mean recoveries of standard addition experiment were between 70.4% and 117.3% for all analytes (RSDs less than 11.5%).