title: Determination of 4,4'-methylenediphenyldianiline (MDA) and identification of isomers in technical-grade MDA in hydrolysed plasma and urine from workers exposed to methylene diphenyldiisocyanate by gas chromatography-mass spectrometry.
abstract: Gas chromatography-mass spectrometry using chemical ionization with ammonia as reagent gas monitoring both positive and negative ions was applied. Negative-ion monitoring using ammonia and the pentafluoropropionic anhydride (PFPA) derivatives were chosen owing to low detection limits and good separation for the isomers studied. Technical-grade methylenediphenyldiioscyanate (MDI) was analysed and three isomers, 4,4'-, 2.4'- and 2,2'-methylenediphenyldianiline (MDA), were determined in addition to methylated MDA. Plasma and urine from an exposed worker were hydrolysed and analysed and the MDA isomers were identified in the biological samples.
authors.affiliation: Department of Occupational and Environmental Medicine, University Hospital, Lund, Sweden.
authors.forename: G
authors.initials: G
authors.lastname: Skarping
authors.forename: M
authors.initials: M
authors.lastname: Dalene
mesh_terms: D000485:Allergens / Q000032:analysis* / Q000097:blood / Q000652:urine; D000814:Aniline Compounds / Q000032:analysis*; D002617:Chemical Industry; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D006868:Hydrolysis; D017953:Isocyanates / Q000032:analysis* / Q000097:blood / Q000652:urine; D007536:Isomerism; D008745:Methylation; D016273:Occupational Exposure; D011140:Polyurethanes; D013048:Specimen Handling; D001559:Benzhydryl Compounds
chemical_list: D000485:Allergens; D000814:Aniline Compounds; D017953:Isocyanates; D011140:Polyurethanes; C005969:4,4'-diphenylmethane diisocyanate; D001559:Benzhydryl Compounds; C009505:4,4'-diaminodiphenylmethane