Hemoglobin adducts from glycidamide:: acetonization of hydrophilic groups for reproducible gas chromatography/tandem mass spectrometric analysis

Acrylamide (AA) is a reactive compound widely used as an industrial chemical. It is also, as recently shown, present in heated foodstuffs. AA is known to cause tumors in rodents and is classified as probably carcinogenic to humans. The metabolite glycidamide (GA) is assumed to be the predominant genotoxic agent in AA exposure. Therefore, knowledge about in vivo doses of GA is essential for cancer risk assessment of exposure to AA. The in vivo dose of GA could be inferred from the level of the adduct formed by GA with N-terminal valine (GA-Val) in hemoglobin (Hb), detached as a pentafluorophenylthiohydantoin (PFPTH) and measured by gas chromatography/tandem mass spectrometric (GC/MS/MS) analysis. However, due to the highly polar character of the GA-Val-PFPTH derivative, it was found necessary to modify the method through further derivatization. This paper presents an evaluation of acetonization for derivatization of the adjacent -OH and -NH2 groups in the adduct formed from GA. Good reproducibility was obtained. Also, acetonization improves the response and thus increases the sensitivity of the GC/MS/MS analysis of the PFPTH derivative of GA-Val. The sensitivity obtained is sufficient for studies of background adduct levels of GA in animals and in humans. Acetonization as a method for derivatization is robust and simple. Copyright (C) 2003 John Wiley Sons, Ltd.