Multi-Residue Screening of Pesticides in Fruit and Vegetables as a Part of the National Residue Monitoring Program 2014

Paulina Goldshlag, Plant Protection and Inspection Services, Ministry of Agriculture and Rural Development, Bet Degan , Israel

Identifying and quantifying pesticides is performed in Pesticide Residue Laboratory under the National residue monitoring program. This program includes analysis of samples from the domestic market, and the screening of samples for the Organic Farming Certification Unit.

The main objectives were monitoring pesticide residues and checking compliance with the MRL`s laid down by Israeli authorities.

Random monitoring programs in 2014 were conducted for over 59 commodities with more than 800 samples, collected for analytical testing. Above 250 pesticides and metabolites were analyzed with multi residue methods by GC-MS,  GC-XSD, GC-FPD and LC-MS/MS. Residues was found in 57 % of samples. The requirement for lower detection limits in complex samples and especially for organic products has driven GC/MS to the limits of acceptable performance.  In 2015 we introduced GC-MS-MS instrument for screening GC amenable pesticides. The GC-MS-MS method was validated for 167 compounds and implemented for analyzing European Union Proficiency Test for Pesticide Residues in fresh herbs (coriander).

As PPIS Laboratory searched for the 176 GC- and LC- amenable pesticides (target list), not only 10 out of 11 (above 90 %)  pesticides with the range of concentration from 41 µg/kg to 668 µg/kg, presented in the test material, detected,  but also no false positives reported. Combined z-score for GC-quantitated pesticides was 0.05.

Results of proficiency tests served as a proof of quality, accuracy and comparability of the residue data reported by PPIS Lab within the framework of national monitoring and surveillance programs.