Mercaptans in malodorants break disulfide bridges in human serum albumin and form adducts suitable as biomarkers of exposure in vitro

Malodorants comprise notoriously smelling mercaptans and might be applied for crowd control. Because exposure to malodorants may lead to irritation of the respiratory system, choking, and coma, bioanalytical verification of poisoning might be required in a medical and forensic context. We herein present the detection and identification of novel biomarkers of exposure to ethyl mercaptan, n-butyl mercaptan, tert-butyl mercaptan, and iso-amyl mercaptan. These alkyl thiol compounds were found to form disulfide adducts in human serum albumin (HSA) in plasma in vitro with the only non-disulfide-bridged Cys