Determination of Abamectin in Soybean Roots by Liquid Chromatography Coupled to Tandem Mass Spectrometry

Abamectin has been used by seed treatment to control plant-parasitic nematodes in Brazil. In this work, foliar spray was performed as an alternative application method and a LC-MS/MS method employing QuEChERS for sample preparation was developed for the analysis of abamectin in soybean roots. For this, abamectin was applied on the leaves and the translocation of this pesticide from leaves to roots was evaluated. The method was validated and presented adequate selectivity. Matrix-matched was used as an approach to calibration. Good linearity of the analytical curve was obtained over the studied range of concentrations from 0.10 to 1.0 mg kg-1, with a determination coefficient of 0.995. The limit of detection was 0.05 mg kg-1, and the limit of quantification was 0.10 mg kg-1. Recoveries were in the range of 99 to 106% and RSD < 20%. Finally, root samples after foliar spray were analyzed, and abamectin was not detected.