Species-Specific Isotope Dilution Analysis and Isotope Pattern Deconvolution for Butyltin Compounds Metabolism Investigations

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• 作者：Pablo Rodr&iacute ; guez-Gonzá ; lez ; André ; s Rodr&iacute ; guez-Cea ; J. Ignacio Garc&iacute ; a Alonso ; and Alfredo Sanz-Medel
• 刊名：Analytical Chemistry
• 出版年：2005
• 出版时间：December 1, 2005
• 年：2005
• 卷：77
• 期：23
• 页码：7724 - 7734
• 全文大小：131K
• 年卷期：v.77,no.23(December 1, 2005)
• ISSN：1520-6882

文摘

A methodology for the study of the absorption andmetabolism of butyltin compounds in laboratory animalsusing isotopically enriched species was developed. Themethod is based on the oral administration of ¹¹⁹Sn-labeled monobutyltin (MBT), ¹¹⁸Sn-labeled dibutyltin(DBT), and ¹¹⁷Sn-labeled tributyltin (TBT) to the animalsand the measurement of both the concentration andisotopic composition of these compounds in the differenttissues by GC-ICPMS. The degradation of butyltin compounds during their metabolism was computed usingleast-squares isotope pattern deconvolution, and theirconcentration was measured by reverse isotope dilutionanalysis using natural-abundance MBT, DBT, and TBTstandards. Male Wistar rats were used as models toevaluate the proposed methodology. Preliminary toxicological results obtained with one rat indicate that TBT ishighly absorbed (64.4%), and it is found in all organs withrelatively high levels in stomach and intestines. Theapparent absorption of DBT was 27.3% and was mainlyfound in liver, kidney, and intestines. However, a largeproportion of the found DBT is formed from the degradation of TBT (~40% of the found DBT in liver is degradedTBT). The apparent absorption of MBT was found to be12.5%, and the originally administered MBT was mainlyrecovered in the feces. However, MBT was clearly detected in liver, kidney, stomach, intestines, and urine asdegradation products of DBT and TBT. Although a significant variability from rat to rat is expected to beobtained, the analytical variability provided by this methodology is small enough to yield meaningful biologicalresults. The results obtained demonstrate that the developed methodology is able to follow qualitatively, quantitatively, and simultaneously the specific metabolic pathways of different species of a given element.