Study On The Determination Of Organotin Compounds In Foods

Organotins(OTs) are widely used as pesticide, fungicide, acaricide, wood preservative, antifouling paint and polyvinyl chloride(PVC) heat stabilizers. OTs have caused different degrees of environmental pollution, even posed some health threaten on human. OTs has been found in different kinds of foods such as seafood from Bohai Bay. Currently, the analysis of OTs focus mainly on environmental samples, few studies have reported on organotin speciation in foods. Therefore, the development of a sensitive analytical method for OTs in foods is important. A method for the determination of methyltin, tributyltin, octyltin and phenyltin in foods has been developed by Grignard derivatization and gas chromatography coupled to tandem mass spectrometry(GC-MS/MS). Meanwhile, a gas chromatography-flame photometric method(FPD) was also developed and comapred with the GC-MS/MS method. The analytical performance of the proposed method, including sensitivity and accuracy, was quite good and it could be further used for routine analysis. The conclusions of this study are listed as follows:(1) A method for the simutaneous determination of 16 OTs in foods was developed by Grignard derivatization and gas chromatography coupled to tandem mass spectrometry. The samples were firstly extracted by Hexane with 0.01% tropolone, followed by derivatization with Grignard reagent(C5H11Mg Br) and purification using Florisil SPE columns. Analysis of the 16 OTs was performed by GC-MS/MS in multiple reaction monitoring(MRM) mode. In the concentration range of 10~1000 μg Sn/kg, the linearity was good, and the limits of detection(LODs) obtained by the proposed method for 16 OTs were 0.3~2.8 μg Sn/kg. The averange recoveries were in the range of 66.9% to 113.2% at the spiked levels of 200 μg Sn/kg with the relative standard deviations(RSDs) ranged from 2.4% to 13.4% except MMT, MBT, MPh T. The proposed method is sensitive and accurate, also with high selectivity, for the simutaneous determination of 16 OTs in foods.(2) A method for the simutaneous determination of 12 OTs in foods was developed by Grignard derivatization and gas chromatography coupled to tandem mass spectrometry. The samples were firstly extracted by Hexane with 0.01% tropolone, followed by derivatization with Grignard reagent(Et Mg Br) and purification using Florisil SPE columns. Analysis of the 12 OTs was performed by GC-MS/MS in MRM. In the concentration range of 10~1000 μg Sn/kg, the linearity was good, the limits of detection(LODs) obtained by the proposed method for 12 OTs were 0.3~0.8 μg Sn/kg. The proposed method is accurate and asensitive, for the simutaneous determination of 12 OTs in foods.(3) A method for the simutaneous determination of 15 OTs in foods was developed by Grignard derivatization and gas chromatography-flame photometric method. The limits of detection(LODs) obtained by the proposed method for 15 OTs were 7~81 μg Sn/kg under the optimized experimental conditions.