L- 古洛糖酸--内酯在普洱茶有机磷农药残留检测中的应用

Application of L-gulonic acid--lactone on determination of organophosphorus residues in Puer tea

摘要: 建立了普洱茶试样中用乙腈提取、石墨化碳柱净化、L- 古洛糖酸--内酯作为分析保护剂、GC-FPD对普洱茶中7种有机磷农药进行定性定量的方法；方法在0.08mg/kg和0.32mg/kg两个添加水平上，添加回收率在76.8%~106.8%之间，变异系数在4.1%~7.7%之间，方法的最低检出限在0.003~0.01mg/kg之间；结果表明，添加L- 古洛糖酸--内酯能显著补偿由基质效应引入的定性定量误差,结果更准确,同时降低了方法的检出限. 

Abstract: An analytical multi-residue method for simultaneous determination of 7 organophosphorus was developed.Pesticides were extracted from Puer tea with acetonitile ,cleaned up on a column of graphite and L-gulonic acid--lactone as an applying analyte protectants ,then were determined by GC-FPD.The recovery studies were performed at 0.08 mg/ kg and 0.32mg/ kg,and the recoveries ranged from 76.8% to 106.8% with a relative standard deviations ranged from 4.1% to 7.7%,and the detection limit of the method ranged from 0.003 to 0.01mg/kg.The results showed that the L-gulonic acid--lactone can provide a more accurate quantitation and compensate matrix-induced chromatophaphic response enhancement,and reduce the detection limit obviously.