文档介绍：固相萃取-高效液相色谱法测定枸杞子中吡虫啉残留量
2009年09月03日何强孔祥虹李建华张莹 
摘要:建立固相萃取-高效液相色谱法测定枸杞子中吡虫啉残留量。样品用乙***提取,中性氧化铝和活性炭固相萃取柱净化,分析时采用Inertsil® ODS-3(25 cm × mm,5μm)色谱柱分离,以乙***-水为流动相梯度洗脱, mL·min-1,检测波长为270 nm,柱温35 ℃。结果表明, mg·L-1~ mg·L-1范围内,吡虫啉峰面积与浓度呈良好的线性关系(r=),枸杞子样品中吡虫啉能得到良好的分离,回收率及重复性良好。该法可用于枸杞子中吡虫啉残留量的检测。
关键词:枸杞子;吡虫啉;高效液相色谱;固相萃取
Determination of imidacloprid resi
-due in Lycium by gradient RP-HPLC HE Qiang, KONG Xiang-hong, LI Jian-hua, ZHANG Ying Abstract Objective: To establish a method for the determination of imidacloprid in Lycium by gradient RP-HPLC. Sample preparation involves extraction with acetonitrile. Final clean-up were performed on an Alumina Neutral SPE Column and an Active Charcoal column, using the column in tandem. Chromatographic analysis was performed on Inertsil® ODS-3(25cm × ,5μm)column. The gradient eluti
on was used with a flow rate of mol·L-1. Mobile phase A: acetonitrile ; Mobile phase B: 0. 01 mol·L-1 potassium dihydrogen phosphate buffer(). Con
Condition of the gradient elution: 0~ 15 min,A: 15%,15~17 min, A from 15% to 30%, 17~25 min, A: 15%; the detection wavelength was 246 nm. Imidacloprid in measured samples was separple
tely. The calibration curve was linear at the range of mg·L-1~ mg·L-1 with good precision and accuracy. The method was applied to the determination of imidacloprid residues in Lycium.
Key words: Lycium; imidacloprid; HPLC; solid phase extraction
吡虫啉(Imidacloprid)是一种内吸性吡啶类杀虫剂,化学名称为1-(6-***-3-吡啶基***)-N-硝基亚咪唑烷-2-基***。吡虫啉具有高效、低毒、广谱的特点,并且对蚜虫、飞虱、叶蝉等害虫有特效。枸杞子为茄科植物宁夏枸杞的干燥成熟果实[1],在宁夏枸杞种植区,该农药是防治枸杞蚜虫的首选药剂,用量较大。近年来,测定吡虫啉残留的方法主要有高效液相色谱法和液质联用法[2~4],但前处理都比较复杂,分离效果不好。
本文建立了梯度洗脱反相高效液相色谱法测定枸杞子中吡虫啉残留量。本方法准确、可靠,对枸杞子中吡虫啉的分离良好,回收率及重复性均符合农药残留测定要求。
1 仪器与试药
Agilent 1200型高效液相色谱系统:配四元泵、DAD检测器、自动进样器及色谱数据处理工作站(美国Agilent公司);旋转蒸发仪(LABOROTA 4001,德国