液相色谱-串联质谱法同时测定8种花草茶中77种农药残留

以QuEChERS作为样品前处理手段，采用高效液相色谱-串联质谱（HPLC-MS/MS）检测技术，建立了适用于8种花草茶中77种农药残留同时检测的方法。8种花草茶样品均采用1%（v/v）乙酸乙腈溶液和1 g乙酸铵提取，经4 g无水硫酸镁、0.50 g C18、0.50 g N-丙基乙二胺（PSA）和0.05 g石墨化炭黑（GCB）分散萃取净化，然后采用Venusil MP C18色谱柱分离，以0.1%（v/v）甲酸水溶液和乙腈为流动相梯度洗脱，在电喷雾电离（ESI）源、正负离子交替扫描模式下进行检测，基质匹配标准溶液定量。结果表明，77种农药在0.5~100.0 μ g/L范围内线性关系良好，相关系数大于0.995；77种农药的加标回收率为70.3%~110.0%，相对标准偏差为2.6%~9.8%，检出限为1.0~10.0 μ g/kg。该法灵敏度、准确度和精密度均符合相关农药残留测定的技术要求。

Simultaneous determination of 77 pesticide residues in eight kinds of herbal tea by liquid chromatography-tandem mass spectrometry

An effective method was developed for the determination of 77 pesticide residues in eight kinds of herbal tea by modified QuEChERS and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The target compounds were extracted with 1% (v/v) acetic acid-acetonitrile and 1 g ammonium acetate, and purified by 4 g MgSO₄, 0.05 g C18, 0.50 g primary secondary amine (PSA) sorbent and 0.05 g graphitized carbon black (GCB). The 0.1% (v/v) formic acid aqueous solution and acetonitrile were used as the mobile phases. The extracts were separated on a Venusil MP C18 chromatographic column using a positive electrospray ionization (ESI) and negative ESI source under the selected ion monitoring (SIM) mode. The analytes were quantified by the matrix match standard solutions. The good linearities were obtained in the range of 0.5-100.0 μ g/L, and the correlation coefficients were all greater than 0.995. The average recoveries of the 77 pesticide residues ranged from 70.3% to 110.0%, and RSDs were in the range of 2.6%-9.8%. The limits of detection were 1.0-10.0 μ g/kg. The method is sensitive, accurate and precise, and can meet the requirements for the determination of pesticide residues.