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Activated carbon (AC) was treated with nitric acid, hydrogen peroxide, and urea. The obtained products were then used as supports for the preparation of palladium/activated carbon (Pd/AC) catalysts. The characterization results revealed that the AC textural structure and surface properties were selectively modified via different treatments, and the surface functional groups of the supports could affect the particle size, dispersion, and chemical states of the Pd nanoparticles. The surface of the urea-treated AC (AC-U) contained more carbonylic groups and nitrogenous species but fewer hydroxylic and carboxylic groups than the surfaces of the ACs subjected to other treatments. Consequently, in the hydrogenation synthesis of meropenem, the Pd/AC-U catalyst provided a higher meropenem yield and lower amounts of impurities in the meropenem product than the other catalysts. The nitrogenous groups not only provided efficient anchoring sites for Pd nanoparticles, improving the reaction activity, but also reduced the side reactions, decreasing the impurity content in the product. [ABSTRACT FROM AUTHOR]

A simple and sensitive method was developed for the determination of three nonsteroidal anti-inflammatory drugs (NSAIDs)—ibuprofen, naproxen and fenbufen in human plasma. The method involved in column liquid chromatographic separation and chemilumenescence (CL) detection based on the CL reaction of NSAIDs, potassium permanganate (KMnO4) and sodium sulfite (Na2SO3) in sulfuric acid (H2SO4) medium. The chromatographic separation was carried out using a reversed-phase C18 column, which allowed the selective determination of the three medicines in the complicated samples. The special features of the CL detector provided lower LOD for determination than that of existing chromatographic alternatives. The results indicated that the linear ranges were 0.01–10.0 μg mL−1 for ibuprofen, 0.001–1.0 μg mL−1 for naproxen, and 0.01–10.0 μg mL−1 for fenbufen. The limits of detection were 0.5 ng mL−1 for ibuprofen, 0.05 ng mL−1 for naproxen and 0.5 ng mL−1 for fenbufen (S/N = 3). All average recoveries were in the range of 90.0–102.3%. Finally, the method had been satisfactorily applied for the determination of ibuprofen, naproxen and fenbufen in human plasma samples. [ABSTRACT FROM AUTHOR]