Study On The Determination Method For Organotin Compounds In Food And Dietary Exposure Assessment Of Chinese Population

Organotins were one group of organic metals which had been widely used. Theirtoxicological effects on human health caused widespread concern internationally. Aselective and sensitive method was developed for the simultaneous determination of18organotin compounds in the processed aquatic food samples using gaschromatography-inductively coupled plasma-mass spectrometry (GC-ICP-MS), with thepurpose of investigating the fifth Chinese total diet study (TDS). Organotins’exposurelevel in food was assessed and the occurrence in several typical kinds of foods wasinvestigated.The organotin compounds were extracted by ultrasonic extraction with methanol. Theextraction and derivatization conditions including the extraction solvent, pH for ethylationand the concentration of the derivatization reagent were optimized. The determination oforganotin compounds in the final extracts was carried out by GC-ICP-MS. The LODs andLOQs of18organotin compounds were in the ranges of0.005~0.010μg/kg (as Sn) and0.010~0.020μg/kg (as Sn), respectively. Spiked recoveries ranged from70.1%to131.6%,with the relative standard deviations (RSDs) from1.1%to9.7%. The results of butyltins ofreference material ERM-CE477by the method of GC-ICP-MS were in good agreementwith the certified values.The method validation results demonstrate that the establishedmethod is sensitive and specific enough for the the analysis of OTCs in complex samples.The proposed method was challenged by analyzing processed aquatic food samplesfrom the fifth Chinese TDS. Eighteen organotin compounds were detected in seventeenaquatic food samples in which containing0.02to7.10ng/g (as Sn). The method could alsobe a reference for the further determination of the organotin compounds in other foodmatrix, and provided a methodology foundation for assessing the organotin compounds inthe average Chinese diet in the general population. The method established above wassuccessfully applied to determine OTCs in the5thTDS samples. A total of206samplesfrom17provines covering12kinds of diet were analysed. TBT was detected in TDSsamples representing39.4%. The highest incidence of butyltins contamination occurred inprocessed aquatic food samples, followed by MBT (82.4%), DBT (88.2%),TBT (88.2%),TrBT (58.8%).The contents of organotins in other kinds of sample determined were verylow. The dietary exposure of butyltins was evaluated for Chinese population. The dietaryexposure assessment of organotins was based on the5thChinese total diet samples and thefood consumption data, the GC-ICP-MS method was used to determine the content ofbutyltins. The result showed that the average dietary exposure of TBT was0.00927μg/kgbw d (as Sn), which accounts for0.7133%of TDI (WHO) and1.5455%of TDI (Japan).The average dietary exposure of butyltins was0.01512μg/kg bw d (as Sn), which accountsfor0.9448%of TDI (WHO) and2.5194%of TDI (Japan). The contents of organotins insample determined were far below the level, and that is to say, our total diet was relativelysafe.