Determination of Carbofuran and Five Organophosphorus Pesticides Simultaneously in Drinking Water by Ultra Performance Liquid Chromatography-Electrospray Tandem Mass Spectrometry

Objective An ultra performance liquid chromatography-electrospray tandem mass spectrometry (UPLC-MS/MS) method was established for the simultaneous determination of dimethoate, dichlorvos, methyl parathion, malathion, chlorpyrifos and carbofuran, in drinking water.

Methods The water samples was filtrated with 0.22 μm PTFE millipore filter after dilutin with methanol-water 1:1, and then injected and detected directly by UPLC-MS/MS. Chromatographic column used for separation was ACQUITY UPLC BETH C₁₈(100 mm×2.1 mm, 1.7 μm). Acetonitrile -water-0.1% formic acid was used as the mobile phase to conduct gradient elution. Identification was achieved by electrospray ionization(ESI+) in multiple reaction monitoring modes. Quantification was performed by the external standard calibration.

Results The calibration curves of 6 pesticides showed good linearity in suitable ranges with correlation coefficient (r) over 0.9990. The detection limits were in the range of(0.05~0.26)μg/L. The recoveries of standard addition were 91.5%~107.4%, and the RSDs were 1.4%~7.1%.

Conclusion The method is simple, rapid, sensitive and suitable for simultaneous determination of six pesticides in drinking water.