正化学源-气相色谱-质谱法测定食用植物油中有机锡化合物残留

建立了正化学源-气相色谱-质谱技术测定食用植物油中有机锡化合物残留的方法。食用油样品经环己烷-乙酸乙酯(1∶1,v/v)溶解后,经凝胶渗透色谱(GPC)净化,目标馏分用四乙基硼酸钠进行衍生。采用基质校正曲线外标法定量,在20～2 000μg/L范围内,7种有机锡化合物均呈现良好的线性关系,相关系数大于0. 99,定量限为0. 3～1. 2μg/kg。对芝麻油样品进行加标回收试验,在0. 05、0. 10、0. 20 m g/kg 3个添加水平下,7种有机锡化合物的平均回收率为66. 2%～103. 2%,相对标准偏差均小于11. 5%。该方法精密度好,灵敏度高,可用于食用植物油中有机锡化合物残留量的测定。

Determination of organo-tin residues in edible vegetable oil by positive chemical ionization-gas chromatography-mass spectrometry

For the determination of organo-tin residues in edible vegetable oil, a method was developed based on gas chromatography-mass spectrometric (GC-MS) with positive chemical ionization (PCI). The edible oil samples were first dissolved by cyclohexane-ethyl acetate (1:1, v/v), and then purified by gel permeation chromatography (GPC). After derivatization by sodium tetraethylborate, the samples were analyzed by GC-MS with PCI source in the single ion monitor (SIM) mode. The seven organo-tin compounds showed good linear relationships in the range of 20-2000 μg/L and the correlation coefficients exceeded 0.99. The limits of quantitation (LOQs) and the average recoveries of the seven organo-tin compounds were 0.3-1.2 μg/kg and 66.2%-103.2%, respectively, and the relative standard deviations were less than 11.5% at three spike levels (0.05, 0.10, and 0.20 mg/kg). The method showed good linearity and high sensitivity and can be used for the determination of organo-tin residues in edible vegetable oil.