高效液相色谱-四极杆-飞行时间质谱法快速筛查胡椒粉中多种农药残留

建立高效液相色谱-四极杆-飞行时间质谱快速筛查胡椒粉中169 种农药残留的分析方法。样品采用0.1%乙酸溶液浸泡，乙腈溶液提取，C18和Florisil吸附剂净化，净化液采用C18色谱柱（100 mm×2.1 mm，2.6 μm）分离，以5 mmol/L甲酸铵溶液-甲醇为流动相，梯度洗脱，在电喷雾正离子模式下检测，基质匹配外标法定量，同时建立169 种农药的一级精确质量数据库和二级碎片质谱库，实现胡椒粉样品中多目标农残的快速定性定量分析。方法验证结果表明，在5～100 ng/mL质量浓度范围内，136 种化合物线性关系良好（R2＞0.95），可进行定量分析，另外33 种化合物可进行定性分析；在3 个加标水平下胡椒粉样品的回收率为26%～140%，相对标准偏差为1.5%～36.0%。该方法操作简便、耗时短，适用于胡椒粉样品中高通量农药残留的快速筛查与定量分析，具有实际应用价值。

Rapid Screening of Pesticide Residues in Pepper Powder by High Performance Liquid Chromatography Coupled with Quadrupole-Time of Flight Mass Spectrometry

An analytical method was established for the simultaneous determination of 169 pesticide residues in pepper powder by high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry(HPLCQ-TOF MS).The samples were soaked in 0.1%(V/V)aqueous acetic acid solution,then extracted with acetonitrile and purified with C18 and Florisil sorbents.The compounds were separated on a C18 column(100 mm×2.1 mm,2.6μm)using gradient elution with a mobile phase composed of 5 mmol/L ammonium formate aqueous solution and methanol,detected in the positive ion mode and quantitated by the matrix matched external standard method.Meanwhile,an accurate mass database and a fragment ion library were created for rapid qualitative and quantitative analysis of the 169 pesticides in pepper samples.The results showed that the method had a good linearity(R2>0.95)within the concentration range of 5–100 ng/mL for 136 pesticide compounds.The remaining 33 compounds could only be qualitatively analyzed.The recoveries for the target compounds at three spiked levels ranged from 26%to 140%,with relative standard deviations of 1.5%–36.0%.The method is simple,less time consuming and suitable for rapid and high-throughput screening of pesticide residues in pepper powder samples.