BACKGROUNDWith the advancement of agricultural intensification and urbanization, pesticide residues in a large numbers of water environments in the world have exceeded the prescribed limit. The issue of pesticide pollution in the water environment has received extensive attention from all sectors of society. As the largest pesticide producer and user country in the world, the amount of pesticide residues in the water environment in China is much higher than other developed countries. Available studies have detected 19 pesticides in seven typical river basins in China (the Yangtze River, Taihu Lake, Yellow River, Songhua River, Heilongjiang, Grand Canal and Dongjiang), with an average concentration ranging from 0.02 to 332.75ng/L. Pesticides and their transformation products pose potential threats to the ecological environment and human health. Research on pesticide residues in the water environment is an indispensable part of water quality assessment. However, targeted screening is difficult to detect unknown pesticides and their transformation products. Therefore, the non-targeted screening of pesticide residues and their transformation products in the environment needs to be improved.

OBJECTIVESTo understand the pesticide pollution analysis techniques for environmental water samples.

METHODSAccording to the analysis process of non-targeted screening of pesticide components, the targeted and non-targeted screening methods for pesticide residues in water quality samples in the past 5 years were reviewed, and the regulations and standards for pesticide residue limits and non-targeted screening of pesticides in water quality were summarized. The research progress of pesticide residue analysis methods in water environment in recent years was summarized.

RESULTSThe characteristics of liquid-liquid extraction (LLE), solid-phase extraction (SPE), solid-phase microextraction (SPME) and other pre-treatment methods were reviewed. Among them, solid-phase extraction was the main pre-treatment method for non-targeted pesticide screening and had good applications prospects. The development trend of analytical instruments from chromatography to chromatography mass spectrometry was discussed, and the production of a variety of high-resolution mass spectrometry provided multi-level analysis requirements for non-targeted pesticide screening. Finally, the guidelines, mass spectrometry database and various identification methods related to pesticide screening confirmation in recent years were summarized, and the development trend of pesticide pollution analysis technology in the water environment was prospected.

CONCLUSIONSHigh resolution mass spectrometry technology poses a challenge to the sample pretreatment and purification process. The combination of multiple technologies in the water sample pretreatment process is the future development trend. Research on non-targeted pesticide screening based on high-resolution mass spectrometry is widely studied in the field of food testing although it has low priority in the environmental field. Relevant organizations at home and abroad have not yet issued relevant standards for screening and confirmation of unknown substances. Currently, the confirmation of unknown screening requires manual data analysis, which cannot be fully automated.