Biomonitoring of acidic biomarkers of occupational exposure and endogenous metabolites in human urine by gas chromatography with mass spectrometric detection
In the study, we report a more comprehensive approach enabling rapid GC-MS screening of sixteen acidic biomarkers in urine that are metabolized in the human body after exposition to several important industrial chemicals.
Figure: An overview of the 16 investigated urinary biomarkers arising in human body after exposure to 8 harmful industrial chemicals
Numerous industrial organic pollutants such as aromates, alkoxyalcohols, other organic solvents and monomers are absorbed, metabolized, and finally excreted in urine mostly as carboxylic acids that are determined as biomarkers of exposure. In the study, we report a more comprehensive approach enabling rapid GC-MS screening of sixteen acidic biomarkers in urine that are metabolized in the human body from several important industrial chemicals; benzene, toluene, styrene, xylenes, alkoxyalcohols, carbon disulfide, furfural and N,N-dimethylformamide. The new method involves simultaneous in situ derivatization – liquid liquid microextraction of urine by an ethyl chloroformate-ethanol-chloroform-pyridine medium and GC-MS analysis of the derivatized analytes. The xenometabolite set represents diverse chemical structures and some of hippuric and mercapturic acids also provided unusual derivatives that were unambiguously elucidated by means of new ethyl chloroformates labeled with stable isotopes and by synthesis of the missing reference standards. In the next step, an automated routine was developed for GC-MS/MS analysis using a MetaboAuto® sample preparation workstation and the new method was validated for fourteen metabolites. Moreover, we show that the new method opens up the possibility for biomonitoring of combined and cumulative occupational exposures of persons exposed to the harmful industrial chemicals simultaneously with endogenous metabolites in human urine samples.
Řimnáčová L., Moos M., Opekar S., Vodrážka P., Pejchal V., Mráz J., Šimek P. (2021) Ethyl chloroformate mediated gas chromatographic-mass spectrometric biomonitoring of acidic biomarkers of occupational exposure and endogenous metabolites in human urine. Journal of Chromatography A 1656, article number: 462547. DOI: 10.1016/j.chroma.2021.462547