Multi-residue method validation of a LC-MS/MS method for quantitative determination of 349 pesticides in tomato and their health risk assessment through monitoring studies

As various pesticides are commonly applied in crop fields, analytical methods based on gas chromatography mass spectrometry (GC-MS) and liquid chromatography mass spectrometry (LC-MS) have been developed. Despite the advantages of these techniques, the market requires the analysis of hundreds of pesticides in a short timeframe but maintaining the sensitivity to assess concentrations below legal limits. To improve the efficiency of analytical methods, the analysis of 349 pesticides in a single chromatographic run was validated for each analyte by determining the analytical parameters according to the criteria described in the SANTE 11312/2021 guide. All the 349 analytes had a recovery between 70-120%, precision < 20%, and as LOQ 0.01 mg/Kg, the lowest acceptable concentration value for pesticides. The method comprises QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) -mediated extraction, followed by LC-MS/MS analysis, eliminating the need for additional clean-up steps. The validated method was used to assess pesticide contamination in 34 tomato samples from Tuscany, observing whether the data obtained were below the legal limits. The 2022 data were compared against samples collected over four years, from 2019. Out of a total of 504 samples, only 8.9% of the 349 targeted pesticides were found. To determine the risk assessment, estimated daily intake (EDI) values were calculated for the total Italian population and for regular consumers. The annual EDI variations were between 1.23E-5 and 2.23E-5 mg/Kg body weight (bw) per day.