State Key Laboratory of Industrial Control Technology, Institute of Cyber-Systems and Control, Research Center for Analytical Instrumentation, Zhejiang University, Hangzhou 310027, China.
College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China.
Sensors (Basel). 2022 Feb 25;22(5):1816. doi: 10.3390/s22051816.
The misuse of pesticides poses a tremendous threat to human health. Excessive pesticide residues have been shown to cause many diseases. Many sensor detection methods have been developed, but most of them suffer from problems such as slow detection speed or narrow detection range. So, the development of rapid, direct and sensitive means of detecting trace amounts of pesticide residues is always necessary. A novel online sensor technique was developed for direct analysis of pesticides in complex matrices with no sample pretreatment. The portable sensor ion source consists of an MPT (microwave plasma torch) with desolventizing capability and an APCI (atmosphere pressure chemical ionization), which provides abundant precursor ions and a strong electric field. The performance which improves the ionization efficiency and suppresses the background signal was verified by using pesticide standard solution and pesticide pear juice solution measurements with an Orbitrap mass spectrometer. The limit of detection (LOD) and the limit of quantization (LOQ) of the method were measured by pear juice solutions that were obtained in the ranges of 0.034-0.79 μg/L and 0.14-1 μg/L. Quantitative curves were obtained ranging from 0.5 to 100 μg/L that showed excellent semi-quantitative ability with correlation coefficients of 0.985-0.997. The recoveries (%) of atrazine, imidacloprid, dimethoate, profenofos, chlorpyrifos, and dichlorvos were 96.6%, 112.7%, 88.1%, 85.5%, 89.2%, and 101.9% with the RSDs ranging from 5.89-14.87%, respectively. The results show that the method has excellent sensitivity and quantification capability for rapid and direct detection of trace pesticide.
农药的滥用对人类健康构成了巨大威胁。过量的农药残留已被证明会导致许多疾病。已经开发出许多传感器检测方法，但大多数方法都存在检测速度慢或检测范围窄等问题。因此，开发快速、直接和灵敏的痕量农药残留检测方法一直是必要的。本文开发了一种新颖的在线传感器技术，用于直接分析复杂基质中无需样品预处理的农药。便携式传感器离子源由具有解溶剂能力的 MPT（微波等离子体炬）和 APCI（大气压化学电离）组成，它提供了丰富的前体离子和强电场。使用农药标准溶液和农药梨汁溶液进行测量，通过 Orbitrap 质谱仪验证了提高电离效率和抑制背景信号的性能。通过梨汁溶液测量，该方法的检出限 (LOD) 和定量限 (LOQ) 在 0.034-0.79 μg/L 和 0.14-1 μg/L 范围内。从 0.5 到 100 μg/L 获得了定量曲线，具有 0.985-0.997 的优异半定量能力的相关系数。莠去津、吡虫啉、乐果、丙溴磷、毒死蜱和敌敌畏的回收率（%）分别为 96.6%、112.7%、88.1%、85.5%、89.2%和 101.9%，RSD 范围为 5.89-14.87%。结果表明，该方法具有优异的灵敏度和定量能力，可用于快速直接检测痕量农药。
