环境水样中农药污染分析技术研究进展

随着农业集约化和城市化的推进,世界上大量水环境中农药残留量已超过规定的限值,水环境中农药污染问题受到社会各界的广泛关注。作为世界上最大的农药生产国和使用国,中国水环境中农药残留量远高于其他发达国家,已有研究表明在我国七个典型流域(长江、太湖、黄河、松花江、黑龙江、大运河和东江)中检测到19种农药,平均浓度范围为0.02～332.75ng/L。农药及其转化产物对生态环境和人体健康具有潜在威胁,水环境中农药残留的研究是水质评估中必不可少的组成部分,而靶向筛查难以检测未知农药及其转化产物。因此,环境中农药残留及其转化产物的非靶向筛查亟需完善。本文依据农药组分非靶向筛查的分析流程,对近五年水质样品中农药残留靶向及非靶向筛查方法进行综述,梳理了近年来国内外食品与水环境中农药残留限量的相关法律法规,对水环境中农药残留分析方法的研究进展进行概述;总结了液液萃取(LLE)、固相萃取(SPE)、固相微萃取(SPME)等样品前处理方法的特点,在这些方法中,固相萃取是农药非靶向筛查的主要前处理方法,具有良好应用前景。本文还探讨了分析仪器从色谱检测到色谱-质谱联用的发展趋势,多种高分辨率质谱的产生为农药非靶向筛查提供了多层次的分析需求;同时通过总结近年来农药筛查确证相关的指导标准、质谱数据库与多种鉴定方法,指出水环境中农药污染分析技术的发展趋势。

A Review of Pesticide Pollution Analysis Techniques for Environmental Water Samples

BACKGROUND: With 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.
OBJECTIVES: To understand the pesticide pollution analysis techniques for environmental water samples.
METHODS: According 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.
RESULTS: The 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.
CONCLUSIONS: High 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.