Simultaneous determination of pesticides and their degradation products in potatoes by MSPD-LC-MS/MS

Abstract The matrix-solid phase dispersion coupled with ultra-high performance liquid chromatography-tandem mass spectrometry was developed and in-house validated to determine pesticides commonly used in crop protection programs dedicated to potatoes and other vegetables. Five pesticides (thiamethoxam, lambda-cyhalothrin, deltamethrin, rimsulfuron and metalaxyl) and five main degradation products were selected for in-house validation and quantification in potatoes. The method showed good accuracy with recovery values between 70-96% and relative standard deviation lower than 10% for all target analytes. The limit of quantification ranged between 0.002 mg kg-1 and 0.051 mg kg-1. The method was used to monitor the target compounds in fifteen potato samples bought at fifteen different local markets in Poland. In eight of the potato samples, at least one pesticide concentration exceeded the maximum residue limit established by the European Union, while in ten of the potato samples, at least one pesticide degradation product was detected. This is the first analytical method for simultaneous determination of pesticides and their degradation products in potatoes that fulfils SANTE/12682/2019 requirements.