Assessment of blood 2-aminothiazoline-4-carboxylic acid concentrations: Age and sex differences, and correlation with carboxyhemoglobin in fire victims.

Recently, 2-aminothiazoline-4-carboxylic acid (ATCA), a cyanide (CN) metabolite, has been proposed as a stable diagnostic marker of CN poisoning. In this study, liquid chromatography coupled with electrospray ionization - tandem mass spectrometry was used to quantify ATCA concentrations in human postmortem blood samples, and differences in ATCA concentrations according to age and sex were determined. Both age and sex had significant effects on blood ATCA concentrations. Although ATCA concentrations exhibited an inverted U shape with increasing age in men, in women ATCA concentrations plateaued at around 40-59 years of age. There were significant differences between the sexes in ATCA concentrations for the 20-39 and 40-59 year age groups (P < 0.05 and P < 0.01, respectively). Correlations between ATCA concentrations and carboxyhemoglobin (CO-Hb) saturation were also examined in fire victims. ATCA concentrations increased significantly with increasing CO-Hb saturation (r = 0.382, P < 0.01). In addition, ATCA concentrations were also correlated to CN concentrations (r = 0.309, P < 0.05). The results of our study may provide novel information about the contribution of CN poisoning to the cause of death at fire scenes.