Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Elimination kinetics of diisocyanates after specific inhalative challenges in humans: mass spectrometry analysis, as a basis for biomonitoring strategies | Budnik et al. Journal of Occupational Medicine and Toxicology 2011 6 9 http content 6 1 9 _ JOURNAL OF OCCUPATIONAL MEDICINE AND TOXICOLOGY METHODOLOGY Open Access Elimination kinetics of diisocyanates after specific inhalative challenges in humans mass spectrometry analysis as a basis for biomonitoring strategies 1 2 3 4 1 Lygia T Budnik Dennis Nowak Rolf Merget Catherine Lemiere and Xaver Baur Abstract Background Isocyanates are some of the leading occupational causes of respiratory disorders predominantly asthma. Adequate exposure monitoring may recognize risk factors and help to prevent the onset or aggravation of these aliments. Though the biomonitoring appears to be most suitable for exposure assessment the sampling time is critical however. In order to settle the optimal time point for the sample collection in a practical biomonitoring approach we aimed to measure the elimination of isocyanate urine metabolites. Methods A simple biomonitoring method enabling detection of all major diamine metabolites from mono- poly-and diisocyanates in one analytical step has been established. Urine samples from 121 patients undergoing inhalative challenge tests with diisocyanates for diagnostic reasons were separated by gas chromatography and analyzed with mass spectrometry GC-MS at various time points 0-24 h after the onset of exposure. Results After controlled exposures to different concentrations of diisocyanates 496 102 ppb-min or 1560 420 ppb-min the elimination kinetics of respective isocyanate diamine metabolites revealed differences between aliphatic and aromatic isocyanates the latter exhibiting a slower elimination and a dose-response relationship. No significant differences were observed however when the elimination time patterns for individual isocyanates were compared in respect of either low or high exposure or in relation to the presence or absence of prior immunological sensitization. Conclusions The detection of isocyanate metabolites in
