A simple and rapid analytical methodology based on liquid chromatography - tandem mass spectrometry for monitoring pesticide residues in soils from Argentina

Abstract

Rapid analytical methodology has been developed for multi-residue determination of pesticides in soils using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) with triple quadrupole analyzer. Soil samples were collected from Argentina in 12 representative agricultural areas, and 18 pesticides were selected on the basis of their use. Special attention was paid to minimize sample preparation, making easier the method application to routine analysis. Several extraction procedures were tested, performing a careful study on matrix effects. The method finally proposed (extraction with acetonitrile and subsequent 2-fold dilution with water without any clean-up step) was fully validated at 0.05 and 0.5 mg/kg on the basis on European SANCO 12571/2013 and 825/00 guidelines. The method applicability and robustness was demonstrated by analysis of quality control (QC) samples, consisting on eleven soils spiked at 0.5 mg/kg. These soil samples were collected from different experimental plots, and were very diverse in their physico-chemical characteristics. The methodology developed is of easy application, there is low consumption of solvents and reagents, and no clean-up is required despite the complexity of the soil matrix. In the near future, the method developed will be used to monitor the presence of pesticides in large agricultural areas of Argentina.