ISSN:
1612-1112
Keywords:
Column liquid chromatography — mass spectrometry
;
Aromatic amines in urine
;
Polyurethane
;
Thermal degradation products
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary An LC-MS method is described for the determination of 4,4′-MDA (4,4′-methylene dianiline) in hydrolysed urine as a biomarker for exposure to 4,4′-MDI (4,4′-methylene diphenylisocyanate). Dideuterated 4,4′-MDA (MDDA) was used as the internal standard. Urine was hydrolysed using sulphuric acid. and 4,4′-MDA was then derivatised with pentafluoro propionic anhydride (PFPA). Thermospray (TSP) and plasmaspray (discharge assisted thermospray, PSP) mass spectrometry monitoring both positive and negative ions were investigated. LC combined with negative ion PSP-MS gave a highly selective and sensitive method of analysis. Quantification was performed monitoring the (M-20)− ions of 4,4′-MDA-PFPA and the MDDA-PFPA. The instrumental detection limit was 0.1 pg/μl of 4,4′-MDA-PFPA. A linear calibration curve was obtained with a The overall precision for human urine spiked to a concentration of 0.5 μg/L was 10% (n=5). The detection limit was about 0.2 μg/l of urine. In technical grade MDA, the precursor of technical grade MDI, several isomers and oligomers with 2–5 aromatic rings were found. In pooled urine samples from ten workers exposed to thermal degradation products of a MDI based polyurethane (PUR) the concentration of 4,4′-MDA was 4 μg/litre. Several MDA isomers and oligomers were observed in the samples.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02268290
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