Simultaneous quantification by LC/ESI-MS/MS of chlorinated tyrosine derivatives in the autopsy sample of a victim of chlorine exposure.

Direct detection and accurate quantification of chlorine in autopsy samples are difficult because of the volatility and rapid metabolism of chlorine. Here, we developed and validated a method for quantitative analysis of 3-chloro-l-tyrosine (Cl-Tyr) and 3,5-dichloro-l-tyrosine (DiCl-Tyr) as stable markers of chlorine exposure. Chemical derivatization followed by liquid chromatography coupled with electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) enabled us to simultaneously analyze both Cl-Tyr and DiCl-Tyr in an autopsy sample from the victim of chlorine exposure. Cl-Tyr was detected in the heart blood (53.6 ng/mL), urine (9.5 ng/mL), and lung tissue (211.1 ng/g); however, DiCl-Tyr was detected only in the lung tissue (10.3 ng/g). In contrast, in autopsy samples obtained from cases without exposure to chlorine, DiCl-Tyr was not detected in any matrixes. Our result suggested that the simultaneous detection of Cl-Tyr and DiCl-Ty may provide a better appreciation of chlorine exposure. To our knowledge, this is the first time Cl-Tyr and DiCl-Tyr have been determined simultaneously in a real human autopsy sample from a victim of chlorine exposure.