Toxaphene, also known as camphechlor, is a persistent organochlorine pesticide of complex composition. It is technically produced by photochlorination of camphene with elemental chlorine gas under ultraviolet irradiation. In the present work, a novel, laboratory-scale synthesis using sulfuryl chloride as a chlorinating reagent is described. This approach allowed the degree of chlorination of the resulting mixtures to be arbitrarily adjusted by varying the reaction conditions. Both the compositions and the chlorine contents of the low- and high-chlorinated mixtures acquired using this method were similar to those of environmentally altered toxaphene and technical toxaphene, respectively. For comparison of these mixtures regarding toxicity, they were subjected to the zebrafish (Danio rerio) embryo test. Median effective concentrations (EC50s) were calculated based on the presence of lethal and nonlethal embryonic malformations. Surprisingly, low-chlorinated toxaphene, comprising compounds that also are present in environmentally transformed toxaphene, exhibited a twofold-higher toxicity (according to the EC50 for nonlethal effects) toward the test organisms compared with high-chlorinated toxaphene, the composition of which resembled that of the technical product. Although the effective concentrations in the embryo test were much higher than those in aquatic ecosystems burdened with toxaphene, the present results lead to the assumption that toxaphene is becoming more toxic during transformation in the environment. A decrease in the total amount of toxaphene during environmental breakdown would then be compensated for, at least in part, by the higher toxicity of weathered toxaphene in sediments, soils, and biota of contaminated ecosystems.
The use of vial closures equipped with butyl rubber septa may lead to sample contamination by rubber additives discharging from the septum material. In this study, the structure elucidation of an artifact causing intense signals in gas chromatography/electron capture negative ion mass spectrometry (GC/ECNI-MS) and gas chromatographic analyses with electron capture detection is described. Tentative identification of the leached compound was achieved by employing tandem mass spectrometric techniques both in electron capture negative ion and in electron ionization modes. The artifact could thus be characterized as 2-benzothiazolyl-N,N-dimethyl dithiocarbamate, which is a known vulcanization accelerator for rubber. It is conceivable that the identified compound or related substances are also used in other applications. Therefore, two food-related matrixes were investigated for a possible migration of this compound into foods. During these analyses, the tentatively identified rubber additive was detected in an aqueous extract of a rubber seal ring for canning jars. GC/ECNI-MS provided better sensitivity and selectivity than GC/EI-MS for the determination of the rubber additive and other mercaptobenzothiazole-derived substances.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.