ABSTRACT
There has been a rapid increase over the last decade in the appearance of new non-controlled psychoactive substances. Minor changes in the chemical structures of these compounds, such as the extension of an alkyl residue or replacement of a single substituent, are regularly made to avoid regulatory control, leading to the manufacture of many new potentially dangerous drugs. Bromoamphetamine analogs (bromoamphetamine [Br-AP] and bromomethamphetamine (Br-MA]) are ring-substituted amphetamines that can behave as stimulants, as well as exhibiting inhibitory activity towards monoamine oxidases in the same way as amphetamines. Gas chromatography-tandem mass spectrometry (GC-MS-MS) was used in this study to differentiate ring-substituted bromoamphetamine analogs. Free bases, trifluoroacetyl derivatives, and trimethylsilyl (TMS) derivatives of six analytes were successfully separated using DB-1ms and DB-5ms columns. Electron ionization MS-MS analysis of the TMS derivatives allowed for the differentiation of three regioisomers. TMS derivatives of 2-positional isomers provided significant product ions. The spectral patterns of 3- and 4-positional isomers were different. Chemical ionization MS-MS analysis of free bases for [M+H-HBr]+ ions at m/z 134 and 148 allowed for differentiation of the regioisomers. The spectra of 2-positional isomers contained characteristic product ions formed by dehydrogenation at m/z 132 and m/z 146 for 2Br-AP and 2Br-MA, respectively. The spectra of 3-positional isomers contained α-cleaved iminium cations as the base peaks. The spectra of 4-positional isomers showed a tropylium cation at m/z 91 as the base peak. These results demonstrate that GC-MS-MS can be used for the differentiation of regioisomeric Br-AP analogs in forensic practice.
ABSTRACT
Arsine (AsH(3))-exposed human blood samples were analyzed by high-performance liquid chromatography with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) for arsenic speciation. After exposure of human blood samples to AsH(3) vapor for 90 min at room temperature, partial hemolysis was observed. Plasma samples from these whole blood samples were prepared by centrifugation at 1600 x g for 10 min and analyzed by HPLC-ICP-MS. In addition to arsenite [As(III); degraded from AsH(3)], an unidentified arsenic species (As-adduct) was detected at a retention time of 1.1 min. Following ultrafiltration of the plasma samples using a molecular weight cut-off of 10 kDa, As-adduct was not detected in the filtrate. To clarify the origin of As-adduct, AsH(3) was added to blank plasma and As(III) was added to both whole blood and hemolyzed blood. Although As(III) was detected in all samples, As-adduct was not detected. These results indicate that As-adduct was derived from erythrocytes during the process of hemolysis by AsH(3) and further suggest that As(III) and plasma ingredients do not contribute to As-adduct production. Therefore, the presence of As-adduct in blood could represent an indicator of acute arsine poisoning.
