高效液相色谱–氢化物发生原子吸收光谱法测定塑料食品包装材料中的有机锡

Determination of Organo Tin Compounds in Plastic Food Packings Materials by High Performance Liquid Chromatography–Hydride Generation–Atomic Absorption Spectrometry

建立了高效液相色谱一氢化物发生原子吸收光谱法同时测定塑料食品包装材料中二甲基锡（DMT）、三甲基锡（TMT）、二丁基锡（DBT）和二苯基锡（DPhT）含量的方法。选择甲醇为溶剂，微波辅助萃取样品中的有机锡化合物，采用Eclipse Plus C18反相柱，在流动相为甲醇一水一乙酸（体积比为65：33：2）的混合溶液中，加入0．05％的三乙胺溶液作为离子对试剂，流速为0．6mL／min时，4种有机锡化合物可达到有效分离。在4％盐酸溶液和2．5％硼氢化钠溶液的氢化反应条件下，4种有机锡化合物质量浓度在5—100μg／L范围内与对应吸收峰面积呈良好线性关系，其相关系数（r）均大于0．999。方法的检出限在0．35-0．50μg／L之间。样品平均加标回收率为86．4％-94．2％，测定结果的相对标准偏差小于7．4％（n=7）。该方法操作简单快速，分离效果好，适用于塑料食品包装材料中有机锡的快速检测。

A method for simultaneous determination of dimethyltin（DMT）, trimethyltin（TMT）, dibutyltin（DBT） and diphenyltin（DPhT） in plastic food packing materials was established by using high performance liquid chromatography- hydride generation-atomic absorption spectrometry （HPLC-HG-AAS）. The sample of plastic food packaging material was treated with methanol by microwave extraction. An Eclipse Plus C18 column was used to separate the four organo tin compounds using methanol-water-acetic acid（volume ratio was 65 ： 33 ： 2） with 0.05% triethylamine as the mobile phase, at flow rate of 0.6 mL/min. The hydrogenation of organo tin compounds reacted in the environment of 4% HCl and 2.5% NaBH4. The four kinds of organo tin compounds（DMT, TMT, DBT and DPhT） had good linear relationship with the corresponding absorption peak area in the range of 5-100μg / L, with correlation coefficients（r） more than 0.999, and the detection limits of the four organo tin compounds were 0.35-0.50 μg/L. The average recoveries were in the range of 86.4%-94.2% for four organo tin compounds with the relative standard deviations below 7.4%（n=7）. The method is feasible and fast for the simultaneous determination of organo tin compounds in plastic food packing materials with simple and convenient operation, efficient sparation and low detection limit.