Mass spectrometric identification of a candidate biomarker peptide from the in vitro interaction of epichlorohydrin with red blood cells

The reaction products of epichlorohydrin with human alpha- and beta- globin s, obtained through in vitro incubation of these compounds and red blood ce lls, were determined by using reversed-phase high-performance liquid chroma tography (RP-HPLC), electrospray ionization mass spectrometry and matrix-as sisted laser desorption/ionization tandem mass spectrometry. The alpha -globin was much more reactive than the beta -globin. At low incu bation ratios, approximating the order of magnitude of epichlorohydrin conc entration as found in workplaces, the only modified peptide still detectabl e was the 62-90 belonging to the alpha -chain and carrying an incremental m ass of 92 u on either His72 or His89, Given that the two peptides co-eluted in a single chromatographic peak during RP-HPLC separation, they could be chosen as suitable biomarkers for quantification in the setting up of a new methodology for the biological monitoring of persons occupationally expose d, replacing currently known procedures. Copyright (C) 2001 John Wiley & So ns, Ltd.