Development and calibration of an integrative passive sampler for monitoring VCM in drinking water networks

This paper evaluates the applicability of a new sampling device for monitoring vinyl chloride monomer (VCM) in drinking water networks. This system consists of an adsorbing cartridge filled with a strong adsorbent enclosed between two sheets of polyethylene-polyamide membrane. The passive sampler (PS) combines preconcentration on the cartridge with easy extraction by thermal desorption into a gas chromatograph (GC), coupled with a tandem mass spectrometer (MS/MS). In order to estimate the suitability of the device for this application, samplers were calibrated in a hydraulic pilot under controlled parameters. The influences of temperature, flow velocity and variation of concentration of exposure were then examined. Linear uptake was observed during a VCM exposure of 12 days and the effect of temperature on the sampling rate was evaluated. This sampling device responds to an aquatic environmental contamination and Public Health issue, both by the organic volatile contaminant monitored in this environment, and by the sampling approach, still little used in drinking water networks. It offers a complementary monitoring to the current technique, providing a more representative assessment of the temporal contamination.

Deregulation of cell cycle and related microRNA expression induced by vinyl chloride monomer in hepatocytes of rats

Vinyl chloride (VC) is a confirmed human carcinogen associated with hepatocellular carcinoma and angiosarcoma. However, the role of microRNAs (miRNAs) in liver cell cycle changes under VC exposure remains unclear, which prevents research on the mechanism of VC-induced carcinogenesis. In this study, male rats were injected intraperitoneally with VC (0, 5, 25, and 125 mg/kg body weight) for 6, 8, and 12 weeks. Cell cycle analysis of liver cells, miRNA-222, miRNA-199a, miRNA-195, and miRNA-125b expression in the liver and serum, and target protein expression were performed at different time points. The results showed a higher percentage of hepatocytes in the G1/G0 and S phases at the end of 6 and 12 weeks of VC exposure, respectively. MiRNA-222 expression decreased initially and then increased, whereas miRNA-199a, miRNA-195, and miRNA-125b expression increased initially and then decreased, which corresponded with changes in cell cycle distribution and related target proteins expression (p27, cyclinA, cyclinD1, and CDK6). The corresponding expression levels of miRNAs in serum did not change. Dynamic changes in miR-222, miR-199a, miR-195, and miR-125b induced by VC can lead to cell cycle deregulation by affecting cell cycle-related proteins, and these miRNAs can serve as early biomarkers for malignant transformation caused by VC.

Construction of activated carbon-supported B3N3 doped carbon as metal-free catalyst for dehydrochlorination of 1,2-dichloroethane to produce vinyl chloride

Metal-free catalysts synthesized by impregnating activated carbons with B3N3-containing arylacetylene resin showed good catalytic performance for industrial dehydrochlorination of 1,2-dichloroethane to produce vinyl chloride monomer.

Synthesis of a vinyl chloride monomer via acetylene hydrochlorination with a ruthenium-based N-heterocyclic carbene complex catalyst

Delocalisation and transfer of electrons in the formed IPr–(Ru) synergistically yields a significant improvement in activity with respect to its counterpart.