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As a typical 3d transition metal, Cu exhibits competitive potential in the catalytic transfer hydrogenation of nitriles due to its low price and appropriate catalytic activity. Unfortunately, the Cu-based catalyst usually requires additional metals to realize good catalytic activity, this makes it difficult to understand the role of Cu. Herein, an amino-modified hollow mesoporous double-shell SiO 2 @C (AmHMSiO 2 @C) microsphere was applied as a nanoreactor, which achieves the high selective hydrogenation of nitriles over the Cu-only catalyst. The conversion and selectivity to primary amines were 100% and 96% respectively at 60 °C using amino borane as the hydrogen source, and the TOF reaches 199.75 h−1 for Cu. The unique structure of the Cu@AmHMSiO 2 @C enhances the activity and stability of the Cu active sites. Comparative experiments demonstrate that the synergy between the nanoreactor and Cu nanoparticles enables the desirable catalytic performance toward the hydrogenation of nitriles to primary amines under mild reaction conditions. This work offers a distinct case for constructing an efficient Cu-based catalyst for heterogeneous hydrogenation reactions. [Display omitted] • Cu@AmHMSiO 2 @C exhibits desirable catalytic performance for the hydrogenation of nitriles to primary amines. • The Cu@AmHMSiO 2 @C nanoreactor exhibited excellent TOF values of 199.75 h−1. • Cu metal, the void-confinement effect, and modified mesoporous SiO 2 @C double-shell are indispensable in this nanoreactor. [ABSTRACT FROM AUTHOR]

Abstract: In recent years, dietary supplements and herbal medicines are increasing in popularity all over the world. However, it is problematic that some manufacturers illegally included synthetic drugs in their products. Due to the extremely complex matrices of those products, most existing methods for screening illegal adulterations are time-consuming and liable to false positive. In this paper, a robust LC/MS/MS method for the high-throughput, sensitive and reliable determination of illegal adulterations from herbal medicines and dietary supplements was established. Minimal LC separation was employed and MRM was used to simultaneously monitor the three transitions under their respective optimal collision energy for each compound. Positive results were determined only if well-defined peaks appeared at all of the three transitions and the ratios among the peak areas were within given threshold. In this study, the method had been applied for the screening of nine most commonly adulterated therapeutic substances, such as sildenafil (Viagra) and famotidine, and the lower limits of detection of these compounds ranged from 0.05 to 1.5ng/ml. Little sample preparation was needed for this method and the analysis time was less than 5min/sample. The reliability has been demonstrated by the test with blank matrix. Over 200 products that were under suspicion by SDA of China had been assayed and till now no false negative or positive result was found. This method is rapid, simple, reliable and capable of screening multiple adulterants in one run. [Copyright &y& Elsevier]

The fabrication of advanced materials for the effective adsorption and monitoring toxic gases in ambient air is highly desirable. The present study reported on the preparation of three-dimensional (3D) porous graphene aerogel (GA) for efficient adsorption and preconcentration of chemical warfare agents (CWAs). A template assisted freeze casting followed by thermal reduction approach was employed to produce hierarchical porous graphene aerogel (HPGA). The resultant HPGA exhibits 3D interpenetrating micron and submicron hierarchical porous structure with excellent thermal stability and large specific surface area, which facilitates rapid diffusion of contaminated gas and thus helps dimethyl methylphosphonate (DMMP) molecules interact with the active adsorption sites through hydrophobic interaction. Thus the higher adsorption capacity was available on HPGA than that of ordinary GA and Tenax TA. For the application, the HPGA was further applied to the extraction of trace sarin from air samples in combination with thermal desorption gas chromatography-mass spectrometry (TD GC-MS). The sorbent exhibited excellent extraction efficiency towards sarin at comparatively high relative humidity owing to its hydrophobic property. The proposed method was reliable and sensitive and can be utilized in ambient air analysis with satisfactory recoveries. [ABSTRACT FROM AUTHOR]

Abstract: Ethnopharmacological relevance: ‘Ershiwuwei Shanhu’ pill (ESP), a classical and famous prescription of traditional Tibetan medicine, has a long history of empirical clinical use for the treatment of cerebrovascular and neurological diseases, but the absence of scientific evidence for its effect restricted its clinical application and further development. Materials and methods: The methodology of plasma pharmacochemistry was adopted to analyze the potentially bioactive components in ESP extracts. A method based on UPLC-DAD/Q-TOF-MS was established to identify herb components in ESP extracts and analyze the absorbed components of ESP and their metabolites in rat plasma, brain, heart, liver and kidney samples after oral administration of ESP extracts. Results: A total of 61 herb components were detected and identified in ESP extracts, while 35 absorbed components—including 19 prototype compounds and 16 metabolites—were discovered as potentially bioactive components in rat plasma and tissues by comparative analysis of the UV and MS chromatograms of ESP extracts, blank biosamples and dosed biosamples. Conclusions: The potentially bioactive components of ESP extracts identified from rat plasma and tissues provide useful information for further study of the pharmacology and mechanism of action of ESP. [ABSTRACT FROM AUTHOR]