Pharmacy School, Qiqihar Medical University, Qiqihar 161006, China.
Molecules. 2022 Aug 12;27(16):5151. doi: 10.3390/molecules27165151.
Numerous studies have shown that pesticide residues in tea exceeding the maximum residue limits (MRL) can cause harmful effects on the human body. There are many limitations in the existing analytical methods for pesticide residues in tea, so new analytical methods need to be developed. We developed a limit test method that combines thin-layer chromatography with Raman imaging microscopy (TLC-RIM). Seven residual pesticide components in tea (Avermectin, Methomyl, Carbendazim, Imidacloprid, Chlorothalonil, Azoxystrobin, and Acetamiprid) could be preliminarily separated by TLC and then irradiated by a 532 nm laser. Raman spectra of seven pesticides obtained by Raman imaging microscopy could be used to test whether the pesticide residues in tea exceed the MRL. The limits of detection of the seven pesticides were 0.04, 0.10, 0.24, 0.20, 0.12, 0.12, and 1.0 mg/mL, respectively. The simulated positive test showed that the matrix in tea did not interfere with the test of the seven pesticides. When the pesticides were tested within 8 h, the RSD of the peak heights of the seven pesticides were 1.2%~9.6%; the test results of three batches of tea showed that the imidacloprid in one batch of tea exceeded its MRL, and the results were consistent with that by UPLC-MS/MS. The TLC-RIM is fast, sensitive, stable, specific, and reliable.
大量研究表明，茶叶中农药残留超过最大残留限量（MRL）会对人体造成有害影响。茶叶中农药残留的现有分析方法存在许多局限性，因此需要开发新的分析方法。我们开发了一种结合薄层色谱和拉曼成像显微镜（TLC-RIM）的限量测试方法。该方法可通过 TLC 初步分离茶叶中的七种残留农药成分（阿维菌素、灭多威、多菌灵、氯噻啉、百菌清、唑菌胺酯和啶虫脒），然后用 532nm 激光照射。通过拉曼成像显微镜获得的七种农药的拉曼光谱可用于测试茶叶中农药残留是否超过 MRL。七种农药的检出限分别为 0.04、0.10、0.24、0.20、0.12、0.12 和 1.0mg/mL。模拟阳性测试表明，茶叶中的基质不干扰对七种农药的测试。当在 8 小时内对农药进行测试时，七种农药的峰高 RSD 为 1.2%~9.6%；对三批茶叶的测试结果表明，一批茶叶中的氯噻啉超过了其 MRL，与 UPLC-MS/MS 的测试结果一致。TLC-RIM 快速、灵敏、稳定、特异、可靠。
