Toluene abuse as a contributing factor in a case of fatal autoerotic asphyxia.

Autoerotic asphyxia is a form of deviant sexual behavior that seeks sexual gratification by means of manipulation with one's own body resulting in asphyxia, and may sometimes turn out to be fatal. Autoerotic fatalities involving autoerotic asphyxia are divided into two groups: "typical" autoerotic fatalities involve mechanical compression of the neck, chest or abdomen, whereas "atypical" autoeroticism involves sexual self-stimulation by other means. Cases where asphyxiophilic behavior is accompanied by volatile substance abuse are reported to be rather rare, but may involve a high risk of fatal results. This paper presents a case of accidental "atypical" autoeroticism involving victim's abuse of toluene, which, combined with asphyxiophilic airway occlusion, led to death. For the sake of comprehensiveness, both a verbal description and a schematic representation of the major metabolic pathways of acute and chronic abuse metabolic markers is provided.

Determination of residual solvents in isobutylboronic acid: Masking derivatization improves stability of GC column.

Masking derivatization was introduced for the determination of residual solvents in samples containing a volatile reactive matrix component(s). Isobutylboronic acid, used in the last step of Bortezomib synthesis, represents a compound passing to the gas phase and deteriorating a chromatographic column during a headspace analysis. The masking derivatization with 1,8-diaminonaphthalene allowed a simple and straightforward conversion of isobutylboronic acid to a stable nonvolatile derivative and thus prevented gas chromatography column deterioration. The method was successfully validated according to the guidelines of International Committee for Harmonization (Q3C (R6) Guideline for Residual Solvents) and international pharmacopoeias (Ph. Eur., USP) and approved by Teva Czech Industries for routine application.

Carbon fiber brush electrode as a novel substrate for atmospheric solids analysis probe (ASAP) mass spectrometry: Electrochemical oxidation of brominated phenols.

A carbon fiber brush electrode (CFBE) was newly designed and used as a substrate for both controlled potential electrolysis and atmospheric solids analysis probe (ASAP) mass spectrometry. Electropolymerized and strongly adsorbed products of electrolysis were directly desorbed and ionized from the electrode surface. Electrochemical properties of the electrode investigated by cyclic voltammetry revealed large electroactive surface area (23 ± 3 cm2) at 1.3 cm long array of carbon fibers with diameter 6-9 µm. Some products of electrochemical oxidation of pentabromophenol and 2,4,6-tribromophenol formed a compact layer on the carbon fibers and were analyzed using ASAP. Eleven new oligomeric products were identified including quinones and biphenoquinones. These compounds were not observed previously in electrolyzed solutions by liquid or gas chromatography/mass spectrometry. The thickness around 58 nm and 45 nm of the oxidation products layers deposited on carbon fibers during electrolysis of pentabromophenol and 2,4,6-tribromophenol, respectively, was estimated from atomic force microscopy analysis and confirmed by scanning electron microscopy with energy-dispersive X-ray spectroscopy measurements.

Study of composition of espresso coffee prepared from various roast degrees of Coffea arabica L. coffee beans.

Espresso coffee samples prepared at various roasting degrees defined according to its basic conventional classification (light, medium, medium-dark and dark roasted) were analyzed by ultra-performance liquid chromatography/tandem mass spectrometry. Obtained raw data were processed using multivariate statistical analysis (Principal Component Analysis, PCA) to evaluate chemical differences between each roasting degrees (untargeted part of study). All four roasting degrees were resolved in appropriate Score plot. Orthogonal Projections to Latent Structures provided signals of significant markers describing the differences among particular roasting degrees. Detailed interpretation of those signals by targeted LC/MS(2) analysis revealed four groups of compounds. The first two groups involve chlorogenic acids and related lactones. The signals of other two sets of markers were ascribed to some specific atractylosides and particular melanoidins. Ratios of contents of selected representatives of each group to the sum of all identified markers were proposed as definite parameters for determination of roasting degree of Brazilian coffee Arabica.

High-performance liquid chromatographic separation of unusual ß(3)-amino acid enantiomers in different chromatographic modes on Cinchona alkaloid-based zwitterionic chiral stationary phases.

Polar-ionic and hydro-organic mobile phase mode of high-performance liquid chromatographic separations of 23 sterically constrained primary ß(3)-amino acid enantiomers containing, alkyl, aryl or heteroaryl side-chains were carried out by using newly developed Cinchona alkaloid-based zwitterionic chiral selectors and the stationary phases Chiralpak ZWIX(+)™ and ZWIX(-)™. In the polar-ionic mode, the effects of the composition of the bulk solvent and the natures of the co- and counter-ions, while in the hydro-organic mode, the effects of the pH, the counter-ion concentration and the structures of the analytes were investigated. The separations of the enantiomers of these 23 primary ß(3)-amino acids, which can be classified as a series of quasi- (pseudo-) homologs, were optimized in both chromatographic modes. The elution sequence was determined in most cases and a reversal of elution order on ZWIX(+)™ and ZWIX(-)™ column was observed. On the basis of this intermolecular recognition model between the selectors and the given enantiomers an indirect assignment of the resolved enantiomer via chromatography is proposed.