APPLICATIONS OF LC MS IN FORENSIC CHEMISTRY

Various analytical techniques for highly sensitive liquid chromatograp hy/mass spectrometry (LC/MS) and their applications in forensic chemis try have been investigated. The following three types of LC/MS instrum ents were used for this study: 1) a Micromass model PLATFORM II equipp ed with an atmospheric pressure chemical ionization (APCI) or an elect rospray ionization (ESI) interface; 2) a Shimadzu model QP-1100EX comb ined with a thermospray TSP interface; 3) a JEOL model JMS-SX102A fitt ed with a Frit - fast atom bombardment ionization (Frit-FAB) interface . Optimization of capillary voltage and the flow rate of the mobile ph ase were found for ESI-LC/MS. The relationship between the composition of mobile phase and ionization efficiency was investigated in the ESI , APCI and TSP types of LC/MS. In ESI-LC/MS analysis, the use of a sem i-micro column (1.5 mm I.D.) allowed about ten rimes more sensitive an analysis than a conventional column (4.6 mm I.D.). In order to examin e the provable period of triazolam, which is quickly metabolized, urin e samples obtained from four volunteers who had taken 0.25 or 0.5 mg o f the drug were analyzed by TSP-LC,IRIS. The main urinary metabolite o f triazolam, alpha-hydroxytriazolam (alpha-HT) was detectable up to 36 hours after taking the dosage. For the purpose of checking the detect able period of suxamethonium in post-mortem biological samples, Frit-F AB LC/MS analysis was performed for the tissue samples of the rats whi ch died by the intraperitoneal administration of the drug at 10 mg/kg bodyweight. Suxamethonium in the rat liver was detectable up to 42 day s later, as long as the bodies were stood at 0 degrees C immediately a fter the death.