固相萃取和分散固相净化-串联质谱测定茶鲜叶和干茶中的农药残留

建立了茶鲜叶和干茶中9种农药的残留分析方法。样品中的残留农药经乙腈提取,Florisil/GCB固相萃取柱和PSA/GCB分散固相联合净化,超高效液相色谱串联质谱（UPLC-MS/MS）和气相色谱质谱联用（GC-MS）测定。在0.005~1.000 mg·kg^-1的添加水平下,目标农药在鲜叶和干茶中的平均回收率在70.3%~103.9%,相对标准偏差（RSD）<20.0%。在0.005~2.000 mg·kg^-1浓度范围,目标农药在鲜叶和干茶基质中的线性关系良好,r>0.995 4。定量限（LOQ）为0.005 mg·kg^-1。实际样品检测结果表明,该方法灵敏度高,重现性好,能够满足农药多残留检测的要求。

Determination of Pesticide Residue in Fresh Tea Leaves and Dry Tea by Solid Extraction and Dispersive Solid Extraction Cleanup Coupled with Tandem Mass Spectrum

A method for the determination of 9 pesticide residues in fresh and dry tea was established. Residual pesticides in samples were extracted by acetonitrile, purified by Florisil/GCB solid phase extraction column, followed by absorbent of PSA and GCB as dispersed solid phase, and determined by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and gas chromatography-mass spectrometry (GC-MS). In the spiked range of 0.005-1.000 mg·kg^-1, the average recoveries of target pesticides in fresh leaves and dried tea were 70.3%-103.9%, and the relative standard deviations (RSD) were less than 20%. In the range of 0.005-2.000 mg·kg^-1, the linear relationship of target pesticides in fresh leaves and dry tea matrix was good, with r>0.995 4. The limit of quantity (LOQ) was 0.005 mg·kg^-1. The test results of actual samples showed that the method was highly sensitive and reproducible, and can meet the requirements of multi-residue detection.