GC-MS/MS法测定玉叶金花中22种有机氯农药残留

Determination of 22 Kinds of Pesticide Residues in Mussarnda pubescens Prescription by Gas Chromatography-Triple Quadrupole Tandem Mass Spectrometry

目的:建立气相色谱-三重四极杆串联质谱法测定玉叶金花中22种有机氯农药残留量的分析方法。方法:玉叶金花样品经乙腈涡旋提取,加入无水硫酸镁,N-丙基乙二胺(PSA),十八烷基硅烷键合硅胶,硅胶,石墨化炭黑(GCB)进行分散固相萃取净化后,再经Florisil固相萃取小柱进行净化,采用气相色谱-三重四极杆串联质谱法在多反应监测(MRM)模式下测定,内标法定量。色谱柱:VF-1701气相毛细管色谱柱(柱长30 m,内径0. 25 mm,膜厚0. 25μm),载气为高纯氮气(99. 999%),流速:0. 8 m L/min,脉冲不分流进样,进样口温度250℃,进样量为1μL,程序升温(初始温度60℃,保持0. 5 min,以每分钟60℃的速率升温至170℃,再以每分钟5℃的速率升温至220℃,保持5 min,再以每分钟1℃的速率升温至240℃,再以每分钟15℃的速率升温至280℃,保持5 min。结果:22种农药成分在5μg/L^200μg/L范围内有良好的线性关系。在范围内,22种农药成分在3个添加水平(0. 01、0. 05、0. 10 mg/kg)下,除六氯苯的加标回收率范围为50. 9%~58. 8%外,其他21种农药成分加标回收率范围为74. 5%~129. 6%,相对标准偏差(RSD,n=3)1. 65%~5. 72%。结论:该方法可应用于玉叶金花中有机氯农药多残留的同时检测。

Objective To develop an analysis method based on gas chromatography- triple quadrupole tandem mass spectrometry （GC- MS/MS） for the determination of 22 kinds of pesticide residues in Mussaenda pubescens. Methods Mussaenda pubescens prescription samples were extracted with acetonitriLe by the vortex extraction, and the extract was purified by dispersive solid phase extraction with sorbents of Magnesium sulfate, primary secondary amine （PSA）, C18, Silica gel and graphitized carbon black （GCB）, then purified through Florisil solid phase extraction （SPE） cartridge. The prepared samples were then analyzed by GC - MS/MS in MRM mode, and the internal standard method was applied to quantify the pesticides. GC was performed on VF - 1701 gas capillary column （ the column length 30 m , diameter 0.25 mm , thickness of 0.25 μm）, The carrier gas was high purity nitrogen at a flow rate of 0. 8 mL · min^-1, The inlet temperature was 250℃, the injection volume was 1 μL, Pulse non shunt injection, The column temperature was raised by program： the initial temperature was 60 ℃, maintained for 0. 5 min, raised to 170℃ with a rate of 60℃·min^ - 1, then raised to 220 ℃ with a rate of 5 ℃·min^-1, maintained for 5 min, raised to 240 ℃ with a rate of 1℃ ·min^- 1, then raised to 280 ℃ with a rate of 15℃·min^-1. Results All the 22 pesticides showed good linearity in the range of 5μg/L to 200 μg/ L. Except the average recoveries of hexachlorobenzene were in the range of 50. 9% to 58. 8%, the average recoveries of all the oether 21 pesticides were in the range of 74. 5% to 129. 6% at three spiked levels of 0. 01, 0. 05, 0. 10 mg/kg, the RSD （ n = 3） were in the range of 1.41% to 6. 10%. Conclusions The method can be used for the muhiresidues anaLysis of organochlorine pesticide residues in Mussaenda pubescens.