基于虚拟模板分子印迹固相萃取的海水中新烟碱类农药检测新方法

Neonicotinoid insecticides are now the most widely used pesticides worldwide and have been widely spread and applied in China. Since there are no reports about the detection method towards neonicotinoids in coastal area, we have no idea about whether the coastal area of China have been polluted and how extend does it be. The key to the problem is the lack of rapid methods for the simultaneous detection of neonicotinoids in seawater. In this project, the dummy template molecularly imprinted technique will be adopted to prepare the new molecularly imprinted polymer to simultaneously recognize 8 commonly used neonicotinoids by optimizing the preparation condition. The optimized polymer was used as solid-phase extraction packing to develop a new solid-phase method which can simultaneously enrich and purify various commonly used neonicotinoids in seawater. A method coupling with high performance liquid chromatography-tandem mass spectrometry will be established which can be applicable to the effectively enrichment, selectively isolation and detecting of various commonly used neonicotinoids in seawater. This method will be applied to the detection of neonicotinoids in Yangtze estuary and its surrounding waters and intend to illuminate the spatial and temporal distribution characteristics of neonicotinoids in this area. This study will provide technical support of neonicotinoids effective detection/monitoring in the coastal area of China and have important realistic and scientific significance in clarifying the pollution status and the scientific evaluation of environmental risk.

新烟碱类杀虫剂是目前世界范围内应用最广的一类农药，我国也在大量生产和使用。目前关于陆地土壤和地表水环境中新烟碱类杀虫剂已有大量研究，但尚未见到近海环境中新烟碱类杀虫剂检测报道。问题的关键是缺乏适用于海水中多种新烟碱类农药同时快速检测方法。本项目拟采用虚拟模板分子印迹技术，通过对聚合条件系统优化，研制能同步特异性识别8种常见新烟碱类农药的分子印迹聚合物；以此聚合物为吸附填料，开发一种能对海水中多种常见新烟碱类农药同步富集、净化的固相萃取新技术，结合高效液相色谱-串联质谱法，建立一种适用于海水中多种常见新烟碱类农药的有效富集、分离检测方法；并将该方法用于长江口及其周边海域环境水体中新烟碱类农药的检测。该研究将为我国近海环境中新烟碱类农药污染物的有效检测/监测提供技术支撑，对阐明我国近海环境中新烟碱类农药的污染现状及环境风险具有重要的科学和现实意义。

新烟碱类杀虫剂是目前世界范围内使用最多、最广的新型杀虫剂，由于其高效低毒，对环境友好安全的特点成为杀虫剂界的新秀。但是近年来，越来越多的研究表明新烟碱对部分生物、尤其是水生甲壳类和蜜蜂等的毒性很高。由于目前关于近海海洋环境中新烟碱类杀虫剂污染的调查研究在全球范围内还未见报道，究其原因主要是缺乏针对海洋环境中高极性新烟碱类农药的同时快速高效检测方法。本项目利用分子印迹的手段结合固相萃取及高相液相色谱-质谱技术，通过不断优化及对比研究开发了一种针对海洋环境中8种常见新烟碱类杀虫剂（吡虫啉、啶虫脒、烯啶虫胺、噻虫啉、噻虫嗪、呋虫胺、噻虫胺、氯噻啉）分离富集检测方法，并应用于中国近岸胶州湾以及长江口近岸海域新烟碱的污染调查研究中。结果显示，胶州湾在入海河水和排污水中以噻虫嗪、吡虫啉和啶虫脒为主，总浓度范围为<LOQ-183.41 ng L−1，平均浓度为12.99 ng L−1。表层海水中以啶虫脒和吡虫啉为主，总浓度范围为<LOQ-4.21 ng L−1。夏季和秋季胶州湾表层海水中的浓度高于春季和冬季。空间上，夏季和秋季表现出较为明显的沿岸浓度高，湾口和湾中心浓度低的空间分布特征；冬季和春季新烟碱类杀虫剂在胶州湾内的分布较为均匀。长江口及其邻近海域表层水中新烟碱类杀虫剂以吡虫啉、噻虫嗪和呋虫胺为主。2017年夏季表层水中新烟碱类杀虫剂的总浓度范围为ND到12.45 ng L−1，平均总浓度为3.37 ng L−1。2018年夏季表层水中新烟碱类杀虫剂的总浓度为ND到99.33 ng L−1之间，平均总浓度为32.83 ng L−1。并表现出近岸浓度高、远岸浓度低的空间分布特征。综上，本研究发展的河水与海水中新烟碱类杀虫剂的检测方法，解决了环境水体中新烟碱类杀虫剂的富集和检测难题，为不同环境介质样品中新烟碱类杀虫剂的检测奠定了基础。