Multiresidue analysis of pesticides in soil by high-performance liquid chromatography with tandem mass spectrometry.

An analytical multiresidue method using HPLC/MS/MS with a triple-quadrupole mass spectrometer in the multiple reaction monitoring mode for the simultaneous determination of 54 pesticides in soil has been developed. The procedure involved initial single-phase extraction of soil sample with acetonitrile by sonication, followed by liquid-liquid partitioning after addition of NaCI. The average recovery by the HPLC/MS/MS method obtained for these compounds varied from 63.2 to 113.8%, with an RSD between 1.9 and 7.1%. The method gave good linearity over the assay range of 10-500 microg/L (except famoxadone, 50-1000 microg/L); the LOD and LOQ for the pesticides varied from 0.02 to 13.2 and from 0.1 to 43.9 microg/kg, respectively. The proposed method was used to determine pesticide levels in soil samples from two experimental vineyards and two tomato greenhouses.