Multi Residual Screening for the Determination of Organoflourine Pesticides in Farm Products Using High Performance Liquid Chromatography (HPLC); Tadem Mass Spectrometry (TMS)

Abstract

Pesticide residues in aquatic products are of great concern due to the risk of environmental transmission and their extensive use in aquaculture. In this work, a quick screening approach was developed for the qualitative and semi-quantitative screening of 87 pesticide residues in aquatic products. The sample preparation was investigated, including extract solvent, extract methods, buffer salts, lipid removal, cleanup materials and filter membranes for aquatic products. Samples were extracted using a modified QuEChERS procedure, and two clean-up procedures were developed for UHPLC-Q/Orbitrap MS analysis based on the fat content of the aquatic products. The screening detection limits for all studied pesticides were distributed between 1 and 500 µg/kg in the three representative matrices. Seventy-one pesticides could be analyzed with a screening limit between 1 and 25 µg/kg in crayfish, sixty-one pesticides could be screened for limits between 1 and 50 µg/kg in crab. The accuracy results showed that recoveries ranged from 50 to 120% for 56 and 52 pesticides at medium-level for crayfish and crab, respectively. At high spiking levels, 65 and 59 pesticides were recovered within the range of 50–120% for the three matrices, respectively. The relative standard deviations of most compounds in different matrices were less than 20%. With this method, the local farmed aquatic products were tested for pesticide residues. In these samples, ethoxyquinoline, prometryn and phoxim were frequently detected. The majority of these confirmed compounds did not exceed 2.00 µg/kg. Two crabs with ethoxyquinoline at 200 µg/kg were detected, indicating the potential dietary risk.