Determination of butyltins in mussel by gas chromatography with flame photometric detection using quartz surface-induced luminescence

A flame photometric detector optimized for the generation of a quartz surface-induced tin luminescence was constructed and evaluated for quantification of butyitins in a mussel tissue. The butyitins were first extracted with toluene, pentylated, preseparated from lipids, and then separated by using gas chromatography. This study confirmed that this quartz surface-induced luminescence for tin, which has an emission maximum at ca. 390 nm, is significantly more sensitive than the much more commonly used SnH gas-phase luminescence at 610 nm. It demonstrated, for the first time, that this blue luminescence is sufficiently stable, reproducible, and rugged to be used for environmental sample analysis provided adequate cleanup is performed. The amount of cleanup practiced in this study was no more rigorous than customarily employed in an analytical laboratory following established protocols. The minimum detectable amounts (MDAs) (defined as the signals that equal 3 times the deviations of the noise) were found to be about 0.3 pg of Sn for tetrapropyitin and about 2-3 pg of Sn for the pentylated derivatives of tri-, di-, and monobutyitin. These MDAs are approximately 30 times better than those reported for using SnH emission. For the mussel samples, the relative MDAs for the butyitins were measured to be about 150 pg of Sn/g of tissue, some 100 times better than those found for using gas-phase luminescence under identical sample workup and similar gas chromatographic conditions

Unexpected synthesis and crystal structure of N-{2-[2-(2-acetylethenyl)phenoxy]ethyl}-N-ethenyl-4-methylbenzenesulfonamide

The title compound, C21H23NO4S, obtained by alkaline treatment of 1,5-bis(1-phenoxy)-3-azapentane at moderate heating, is a N-tosylated secondary vinylamine. An intramolecular S=O⋯H - C hydrogen bond generates a 13-membered ring. The benzalacetone moiety adopts a trans conformation with respect to the C=C double bond, which is slightly longer than usual due to the conjugation with a neighbouring acetyl group. Theoretical predictions of potential biological activities were performed, suggesting that the title compound can inhibit gluconate 2-dehydrogenase (85% probability), as well as to act as a mucomembranous protector (73%). © 2020

A review on advances in graphene-derivative/polysaccharide bionanocomposites: Therapeutics, pharmacogenomics and toxicity

Graphene-based bionanocomposites are employed in several ailments, such as cancers and infectious diseases, due to their large surface area (to carry drugs), photothermal properties, and ease of their functionalization (owing to their active groups). Modification of graphene-derivatives with polysaccharides is a promising strategy to decrease their toxicity and improve target ability, which consequently enhances their biotherapeutic efficacy. Herein, functionalization of graphene-based materials with carbohydrate polymers (e.g., chitosan, starch, alginate, hyaluronic acid, and cellulose) are presented. Subsequently, recent advances in graphene nanomaterial/polysaccharide-based bionanocomposites in infection treatment and cancer therapy are comprehensively discussed. Pharmacogenomic and toxicity assessments for these bionanocomposites are also highlighted to provide insight for future optimized and smart investigations and researches. © 2020 Elsevier Lt