固相萃取-离子交换色谱法测定浓缩苹果汁中残留的苯菌灵、多菌灵、噻菌灵

Determination of benomyl,carbendazim and thiabendazole in apple juice concentrate using solid-phase extraction coupled with ion exchange chromatography

建立固相萃取-离子交换色谱法测定浓缩苹果汁中苯菌灵、多菌灵和噻菌灵的残留量。样品直接用水稀释后,于80℃下将苯菌灵完全转化为多菌灵,再经SCX固相萃取柱富集,采用LC-SCX离子交换色谱柱(25cm×4.6mm,5μm)分离,二极管阵列检测器检测,以0.1mol/LKH2PO4溶液(pH2.5)-乙腈(体积比为70∶30)为流动相,在1.0mL/min下等度洗脱,于282nm波长下检测。在0.02～2.0mg/L范围内,多菌灵和噻菌灵的峰面积与其浓度呈良好的线性关系,最低检出限均可达到0.004mg/kg,回收率为94.2%～100.4%,相对标准偏差低于4.2%。该方法简便、快速、灵敏、准确,可用于浓缩苹果汁中苯菌灵、多菌灵和噻菌灵残留量的检测。

A method was developed for the determination of benomyl,carbendazim and thiabendazole in apple juice concentrate by solid-phase extraction coupled with ion exchange chromatography（IEC）.The sample was diluted with water,and then benomyl was degradated completely to carbendazim at 80 ℃,and purified by an SCX solid-phase extraction column.Liquid chromatographic analysis was performed on the instrument of Agilent 1200 series equipped with a diode-array detector and autosampler.The column was LC-SCX（25 cm×4.6 mm,5 μm）.The mobile phase was 0.1 mol/L KH2PO4（pH 2.5）-acetonitrile（70∶30,v/v）with a flow rate of 1.0 mL/min.The presented method showed good linear relationship with good precision and accuracy at the range of 0.02-2.0 mg/L for carbendazim and thiabendazole.The detection limits were 0.004 mg/kg for carbendazim and thiabendazole.The method was characterized with acceptable sensitivity to meet the requirements for monitoring these pesticides in apple juice concentrate.