气相色谱-质谱联用法测定PVC塑料制品中的微量有机锡

建立了一种可同时测定聚氯乙烯(PVC)塑料制品中一丁基锡、二丁基锡、三丁基锡、四丁基锡、一辛基锡、二苯基锡和三苯基锡等7种有机锡化合物的气相色谱-质谱(GC-MS)检测方法。利用三水合二乙基二硫代氨基甲酸钠(NaDDTC)与有机锡的螯合作用,以甲醇-NaDDTC水溶液(2%,m/v)的混合溶液浸取PVC样品中的有机锡,经四乙基硼酸钠(NaBEt4)水溶液衍生化后,用正己烷萃取分离,再进行GC-MS的定性定量分析。对样品前处理过程、衍生化条件、色谱条件等进行了优化,并考察了方法的线性关系、检出限、回收率和精密度等。方法的线性范围为0.1～50.0 mg/L,线性相关系数为0.999 0～0.999 8。有机锡化合物的检出限为0.005～0.025 mg/L,样品加标回收率为87.64%～110.16%,相对标准偏差皆小于10%。结果表明,该法简便、灵敏,能很好地应用于PVC制品中微量有机锡的测定。

Trace Determination of Organic Tin in PVC Plastic Products by GC-MS

A kind of gas chromatogram-mass spectrometry method(GC-MS) for simultaneous determination of 7 kinds of organotin compounds(OTs),such as monobutyltin(MBT),dibutyltin(DBT),tributyltin(TBT),tetrebutyltin(TeBT),monooctyltin(MOT),diphenyltin(DPhT) and triphenyltin(TPhT),which exist in polyvinyl chloride(PVC) plastic products was established.The method is based on sodium diethyldithiocarbamate(NaDDTC) chelation of ionic organic tin.Trace amounts of OTs in PVC samples were extracted by the mixture of methanol and NaDDTC aqueous solution(2%,m/v),followed with derivatization by sodium tetraethylborate(NaBEt4) and extraction by hexane,then detected by GC-MS.The extraction,derivatization and GCMS conditions were optimized.Performance characteristics such as linearity,detection limit,recovery and precision were obtained.The linearity is satisfactory over a range of 0.1～50.0 mg/ L with regression coefficients of 0.999 0～0.999 8.Detection limits are between 0.005～0.025 mg/L.The average recoveries of OTs range from 87.64% to 110.16%,with relative standard deviations(RSDs) lower than 10%.The results prove that:this simple and sensitive method has been successfully applied to determination of trace amounts of OTs in PVC plastic samples.