Engineering (Apr 2020)
Simultaneous Screening of 733 Pesticide Residues in Fruits and Vegetables by a GC/LC-Q-TOFMS Combination Technique
Abstract
In this paper, we report the construction of two accurate mass databases and the development of a combination detection method that simultaneously screens for 733 pesticide and chemical contaminant multi-residues via high-throughput gas chromatography (GC)– and liquid chromatography (LC)–quadrupole-time-of-flight mass spectrometry (Q-TOFMS). This work demonstrates that electronic mass spectral standards may replace chemical-source standard materials as references through one sample preparation and the combination of GC/LC–Q-TOFMS screening. This cutting-edge technique has also replaced multi-residue determination using targeted detection with non-targeted screening. The pesticide residue types, sensitivity, recovery, and reproducibility of this combination technique are evaluated in eight fruit and vegetable matrices. This technique shows three advantages: ① In comparison with the discovery capability of a single technique, the combination technique shows an improvement of 51.1% (GC–Q-TOFMS) and 39.6% (LC–Q-TOFMS), respectively; ② the combination technique can satisfy a screening limit lower than 10 μg·kg−1 and meet the requirements of “uniform standards,” although some of the pesticide residues could be optimized to further improve screening sensitivity; ③ over 488 pesticides with recoveries between 60% and 120% and relative standard deviation (RSD) ≤ 20% at a spiked level of 10 μg·kg−1 were detected with the combination technique in eight different matrices. From 2012 to 2017, this combination technique was applied in an investigation to screen pesticide residues from 1384 sampling locations for 38 138 batched samples covering 18 categories and 134 types of fruits and vegetables obtained from across the mainland of China. After statistical analysis, 533 pesticides in 115 891 determinations were detected, and the regularity of pesticides in the fruits and vegetables sold on the Chinese market was shown.