Determination of isocyanate specific albumin-adducts in workers exposed to toluene diisocyanates

Abstract

Toluene diisocyanates (2,4-TDI and 2,6-TDI) are important intermediates in the chemical industry. Among the main damages after low levels of TDI exposure are lung sensitization and asthma. It is therefore necessary to have sensitive and specific methods to monitor isocyanate exposure of workers. Urinary metabolites or protein adducts have been used as biomarkers in workers exposed to TDI. However, with these methods it was not possible to determine if the biomarkers result from exposure to TDI or to the corresponding toluene diamines (TDA). This work presents a new procedure for the determination of isocyanate-specific albumin adducts. Isotope dilution mass spectrometry was used to measure the adducts in albumin present in workers exposed to TDI. 2,4-TDI and 2,6-TDI formed adducts with lysine: N^ϵ-[({3-amino-4-methylphenyl}amino)carbonyl]-lysine, N^ϵ-[({5-amino-2-methylphenyl}amino)carbonyl]-lysine, and N^ϵ- [({3-amino-2-methylphenyl}amino)carbonyl]-lysine. In future studies, this new method can be applied to measure TDI-exposures in workers.

Keywords::

• Mass spectroscopy
• chemical carcinogenesis
• environmental Pollution/Ecotoxicology

Acknowledgements

This research was supported by the Tulane Cancer Center.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.