A novel approach for identification and measurement of hemoglobin adducts with 1,2,3,4-diepoxybutane by liquid chromatography/electrospray ionisationmass spectrometry and matrix-assisted laser desorption/ionisation tandem mass spectrometry

The structural characterisation of the adducts formed by in vit ro interact ion of hemoglobin (Hb) with 1,2,3,4-diepoxybutane (DEB), the most reactive 1,3-butadiene (BD) metabolite, was obtained by liquid chromatography/electr ospray ionisation mass spectrometry (LC/ES-MS) analysis of modified tryptic peptides of human hemoglobin chains. The reactive sites of human hemoglobi n towards DEE and its hydroxylated derivatives (trihydroxybutyl (THB)-deriv atives) were identified through the characterisation of alkylated tryptic p eptides by matrix-assisted laser desorption/ionisation tandem mass spectrom etry (MALDI-MS/MS). Based on this characterisation, a procedure was set up to measure the Hb-adducts of THE-derivatives by isotope dilution mass spect rometry with the use of a deuterated peptide standard. The results obtained here could permit optimisation of molecular dosimetry of BD-adducts, and e xtension of the analysis to the biological monitoring of occupational expos ure to butadiene. Copyright (C) 2001 John Wiley & Sons, Ltd.