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1000
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Abstract/Summary
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The method permits the simultaneous quantification of the N‐terminal haemoglobin adducts N‐(2‐hydroxyethyl)valine (HEV), N‐(2‐hydroxypropyl)valine (HPV), N‐(2‐cyanoethyl)valine (CEV), N‐(2‐carbonamide ethyl)valine (AAV), and N‐(2‐hydroxy‐2‐carbonamide ethyl)valine (GAV) of the carcinogens ethylene oxide, propylene oxide, acrylonitrile, acrylamide, as well as of glycidamide the metabolite of acrylamide in blood. The adducts which are covalently bound to the N‐terminal valine of the globin chain are cleaved off from the globin chain by a modified Edman degradation. The resulting pentafluorophenyl thiohydantoine derivatives of the valine adducts are extracted with diethyl ether, purified and then subjected to tandem mass spectrometric detection. To protect the vicinal hydroxyl group of the glycidamide adduct, the modified Edman degradation is followed by a second derivatization using sulphuric acetone. For calibration, standards are prepared in non‐smoker pooled globin, adding solutions of dipeptide standards simulating the adduct‐bearing latter two N‐terminal amino acids of the haemoglobin chain. They are processed in the same way as the samples to be analyzed. As internal standards, solutions of isolated globin, which has prior been transformed with the deuterated compounds d3‐acrylo‐nitrile, d3‐acrylamide or d3‐propylene oxide, are used. As internal standard for glycidamide, the d8‐labeled, acetonized pentafluorophenyl thiohydantoine of the glycidamide valine adduct is used.
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