Photocatalytic conversion of biomass derived chemicals to valuable products is a highly sustainable process. Herein we report the photocatalytic hydrogenation of maleic acid to succinic acid and oxidation of 5-hydroxymethylfurfural...

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We report a multi-residue pretreatment technique, termed temperature-assisted ionic liquid dispersive liquidliquid microextraction, and demonstrate its application to simultaneous extraction of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). An ionic liquid was used as the extraction solvent and dispersed into the liquid sample (water, urine) with the help of methanol and at elevated temperature. Parameters such as extraction solvent and its volume, disperser solvent and its volume, extraction time, centrifugation time, salt addition, extraction temperature and sample pH were optimized. Under the optimized conditions, an up to 278-fold enrichment factor and an >83.4% extraction recovery were obtained. A linear relationship is obtained in the range of 0.5-500 ng mL −1 . The limits of detection (at S/N03) and relative standard deviations (for n05) range from 0.1 to 0.4 ng mL −1 and from 1.0% to 5.6%, respectively. The recoveries for water and urine samples additionally spiked with PCBs and PBDEs are between 81.0 and 127.1% and 84.0 and 110.3%, respectively. The method was successfully applied to the determination of PCBs and PBDEs in real river water and in human urine samples.

SummaryTwo new kinds of calix [4]arene derivatives, 5,11,17,23-tetra-tert-butyl-25,27-bis(isopropylcarbamoyl-meth- . These stationary phases demonstrate high column efficiencies, wide operating temperature ranges, good thermal stability and excellent selectivity for aromatic isomers, especially phenol compounds. Their inclusion properties are also discussed.

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