No abstract

A validated GC-MS method for the analysis of urinary metabolites of alkyl benzenes is reported. Metabolites for exposure to toluene, xylene and ethylbenzene were analyzed simultaneously using stable isotope substituted internal standards. The method entailed acidic deconjugation of urine samples followed by extractive alkylation with pentafluorobenzyl bromide as alkylating agent. The resulting pentafluorobenzyl derivatives of ortho-, meta-, para-cresol, mandelic acid (MA), hippuric acid (HA) and ortho-, meta-, para-methylhippuric acid (MHA) were then quantified by SIM. Optimized reaction conditions for the extractive alkylation step are reported. The derivatives were found to be sufficiently stable for overnight batch analysis. The LODs were below 0.1 micromol/L for the cresols and below 1 micromol/L for MA and the HAs. Within-batch precision for o-MHA was 7%, for m-MHA 5%, for p-MHA 5.2% and below 5% for the rest of the analytes.

A bystander claimed to have been shot by a police officer, and CT scans were used to match qualitative and quantitative aspects of the unremoved bullet with police issued 9 mm Luger ammunition. CT scan methodology proved a valid approach for the measurement of bullets based on calculated measurement capability and correlation with "gold standard" physical measurement by vernier caliper. Measurements regarding length and base diameter, as well as length/diameter ratio, were insufficient to unambiguously identify a specific caliber, or a bullet of specific mass within a caliber class. It was, however, possible to exclude a bullet of specific design and mass with well-characterized precision and accuracy values under selected CT scan conditions. A 9 mm Luger bullet (115 gr FMJ RN) was excluded from involvement in a shooting based on qualitative bullet shape combined with length, base, and ratio measurements of the bullet in-situ for the victim.

The coca family (Erythroxylaceae) consists of trees and shrubs sub-divided into four genera:Aneulophus, Nectaropetalum, Pinacopodium, and Erythroxylum, which include species with highly valuable medicinal compounds. E. delagoense, E. emarginatum, and E. pictum are endemic to southern Africa and have great pharmaceutical potential based on their traditional uses. Previous studies have shown certain inconsistencies in terms of the presence or absence of tropane alkaloids in these species, resulting in a need for further research and clarification. Therefore, the aim of this study was to determine the seasonal variation of the immediate biosynthetic precursor of cocaine, the tropane alkaloid, ecgonine methyl ester in the three South African Erythroxylum species by means of gas chromatography -mass spectrometry, as well as to conduct a phytochemical screening for observing the presence of other potential compounds and tropane alkaloids. We found significant differences in tropane concentrations from the seasonal variation study, explaining the discrepancies in previous reports on its presence/absence in these species. Furthermore, we report for the first time on the occurrence of selected highly valuable tropane alkaloids in E. emarginatum currently used in 'blockbuster-medicine'.