固相萃取-气相色谱法测定食用菌中有机磷农药残留

Determination of organophosphorus pesticides residue in mushroom by SPE-GC

目的建立一种固相萃取-气相色谱法测定食用菌中22种有机磷农药残留的方法。方法食用菌被乙腈匀浆、超声、振荡提取,无水硫酸钠脱水,浓缩后经固相萃取柱净化,氮气吹干,以丙酮定容,再通过DM-17毛细管柱和PFPD检测器定性、定量。结果22种有机磷农药的分离效果好,线性相关系数均>0.99,最低检出限为0.000 18 mg/kg^0.035 mg/kg,平均回收率为68%~116%,RSD为2.1%~5.8%。结论该方法具有快速、简便、准确度和精密度好的优点,适合食用菌中多种有机磷农药残留的检测。

Objective To establish a method for the determination of 22 organophosphorus pesticides residue in mushroom by solid- phase extract- gas chromatography（ SPE- GC）. Methods The samples were homogenated and extracted by acetonitrile,dehydrated by anhydrous sodium and purified by solid phase extraction after being concentrated,the sample solution was dried by nitrogen gas,the residue was dissolved in acetone and analyzed by gas chromatography with DM- 17 and pulse flame photometric detector for qualification and quantification. Results The pesticides were separated from each other very well. All of their linearity was more than 0. 99. The detection limits were from 0. 000 18 mg / kg to 0. 035 mg / kg. The average recovery rates were from 68% to 116% with relative standard derivations of 2. 1% to 5. 8%. Conclusion This method is rapid,simple,accurate and reliable. It can be applied to determine the organophosphorus pesticide multi- residues in mushroom.