Qualitative and quantitative analysis of human hemoglobin-carcinogen adducts has potential as a diagnostic tool for estimation of biologically effective levels of carcinogen exposure and for attaining a better understanding of individual susceptibility to chemical carcinogenesis. The purpose of this study was to devise a strategy for preanalytical enrichment of the class of covalent human hemoglobin-carcinogen adducts formed by reaction at the hemoglobin beta 93 cysteine sulfhydryl groups. The results define a charge-shift strategy in which a mixture composed of natural hemoglobin (Hb-SH) and low levels of hemoglobin-S-xenobiotic adducts (Hb-SX) is treated with an anionic sulfhydryl reagent (R-), followed by anion-exchange liquid chromatographic separation of Hb-SR- from the unreactive Hb-SX adducts. Using 4-(iodoacetamido)-salicylic acid as the charge-shift reagent, we applied the strategy to the isolation of chromatographically similar adducts with either 4-nitrosobiphenyl or [3H]-N-ethylmaleimide. The strategy was effective for adduct concentrations less than or equal to 10 mumol/mol of hemoglobin. Application of the strategy provides an adduct-enriched fraction useful for subsequent analysis using either currently available techniques or alternate chemical or biochemical techniques that may be designed to take advantage of the enrichment procedure.
Aminobiphenyl Compounds Biphenyl Compounds