Chen Hongping, Wang Xinlu, Liu Pingxiang, Jia Qi, Han Haolei, Jiang Changling, Qiu Jing
Institute of Quality Standards and Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences, Key Laboratory of Agri-food Quality and Safety, Ministry of Agriculture and Rural Affairs, Beijing 100081, China.
Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Foods. 2021 Jan 18;10(1):189. doi: 10.3390/foods10010189.
Pyrethroid pesticides are widely used on tea plants, and their residues of high frequency and concentration have received great attention. Until recently, the residues of typical metabolites of pyrethroid pesticides in tea were unknown. Herein, a modified "quick, easy, cheap, effective, rugged and safe" (QuEChERS) method for the determination of three typical metabolites of pyrethroid pesticides in tea, using ultra performance liquid chromatography tandem mass spectrometry, was developed. The mixture of florisil, octadecylsilane, and graphite carbon black was employed as modified QuEChERS adsorbents. A Kinetex C18 column achieved good separation and chromatographic peaks of all analytes. The calibration curves of 3-phenoxybenzoic acid (3-PBA) and 4-fluoro-3-phenoxybenzoic acid (4-F-3-PBA) were linear in the range of 0.1-50 ng mL (determination coefficient R higher than 0.999), and that of -3-(2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylic acid (TFA) was in the range of 1-100 ng mL (R higher than 0.998). The method was validated and recoveries ranged from 83.0% to 117.3%. Intra- and inter-day precisions were lower than or equal to 13.2%. The limits of quantification of 3-PBA, 4-F-3-PBA, and TFA were 5, 2, and 10 μg kg, respectively. A total of 22 tea samples were monitored using this method, and 3-PBA and TFA were found in two green tea samples.
拟除虫菊酯类农药在茶树中广泛使用，其高频率和高浓度残留备受关注。直到最近，拟除虫菊酯类农药在茶叶中的典型代谢物残留情况仍不明确。在此，开发了一种改进的“快速、简便、廉价、高效、耐用和安全”（QuEChERS）方法，用于测定茶叶中拟除虫菊酯类农药的三种典型代谢物，采用超高效液相色谱串联质谱法。使用弗罗里硅土、十八烷基硅烷和石墨化炭黑的混合物作为改进的QuEChERS吸附剂。Kinetex C18柱实现了所有分析物的良好分离和色谱峰。3-苯氧基苯甲酸（3-PBA）和4-氟-3-苯氧基苯甲酸（4-F-3-PBA）的校准曲线在0.1 - 50 ng/mL范围内呈线性（测定系数R高于0.999），而-3-(2-氯-3,3,3-三氟丙-1-烯-1-基)-2,2-二甲基环丙烷羧酸（TFA）的校准曲线在1 - 100 ng/mL范围内（R高于0.998）。该方法经过验证，回收率在83.0%至117.3%之间。日内和日间精密度均低于或等于13.2%。3-PBA、4-F-3-PBA和TFA的定量限分别为5、2和10 μg/kg。使用该方法共监测了22个茶叶样品，在两个绿茶样品中检测到了3-PBA和TFA。
