超高效液相色谱-四极杆-飞行时间质谱法快速筛查香橼中180种农药残留

建立了QuEChERS法结合超高效液相色谱-四极杆-飞行时间质谱 (UPLC-Q-TOF/MS)快速筛查香橼中180种农药多残留的方法。通过优化样品前处理净化方式及保留时间窗口、精确质量数提取窗口和绝对峰面积阈值 (peak filter)等主要检索参数,建立了精确质量数数据库和高分辨碎片离子谱图库,并对筛查方法的定性及定量结果进行了验证。结果表明:在0.005~1 mg/L质量浓度范围内,180种农药在香橼中的线性关系良好( r > 0.99),其中96.6%的农药筛查限 (SDLs)均低于0.05 mg/kg。在0.02、0.05和0.1 mg/kg 3个添加水平下,180种农药在香橼中的平均回收率分别为58%~129%,68%~131%和66%~132%,相对标准偏差 (RSD)在0.7%~18% (n = 5)之间。该方法利用TOF-MS一级精确质荷比筛查并结合高分辨碎片质谱图确证,提高了多农药残留快速筛查的准确性,有效降低了假阳性率,对中药材香橼中农药残留的日常监测具有普遍适用性。

Rapid screening of 180 pesticide residues in Fructus Citri by ultra performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry

A rapid screening method for multi-residue of 180 pesticides in Fructus Citri was established by QuEChERS combined with ultra-performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (UPLC-Q-TOF/MS). An accurate mass database and a high-resolution fragment ion spectrum library were established by optimizing the sample preparation and purification, as well as the search parameters such as the accurate mass extraction window, the retention time window and the absolute peak filter. Moreover, the qualitative and quantitative results of the proposed screening method were verified. The results showed that the linear relationship of the 180 pesticides in Fructus Citri was good within the mass concentration range of 0.005-1 mg/L (r > 0.99), and the screening detection limits (SDLs) of 96.6% of the pesticides were below 0.05 mg/kg. The average recoveries at the three spiked levels (0.02, 0.05, 0.1 mg/kg) were 58%-129%, 68%-131% and 66%-132%, respectively, and the relative standard deviation (RSD) was 0.7%-18% (n=5). Using TOF-MS first-level accurate mass-to-charge ratio screening combined with the confirmation of high-resolution fragment mass spectrometry, the proposed method significantly improved the accuracy of rapid screening for multiple pesticide residues, efficiently reduced the false positive rate, and has universal applicability in the daily monitoring of pesticide residues in Chinese medicinal materials of Fructus Citri.