Development and validation of a high-performance liquid chromatography-electrospray ionization-mass spectrometry assay for the determination of zaleplon in human plasma

In this paper, a sensitive and rapid chromatographic procedure using a selective analytical detection method (electrospray ionization-mass spectrometry in selected-ion monitoring mode) in combination with a simple and efficient sample preparation step is first presented for the determination of zaleplon in human plasma. The separation of the analyte, internal standard, and possible endogenous compounds are accomplished on a phenomenex Luna 5-microm C8(2) column (250- x 4.6-mm i.d.) with methanol-water (75:25, v/v) as the mobile phase. In order to optimize the mass detection of zaleplon, several parameters such as ionization mode, fragmentor voltage, m/z ratios of ions monitored, type of organic modifier, and eluent additive in the mobile phase are discussed. An internal standard is selected to guarantee the quantitative accuracy. Each analysis takes less than 6 min. The calibration curve of zaleplon in the range of 0.1-60.0 ng/mL in plasma is linear with a correlation coefficient of > 0.9992, and the detection limit (s/n = 3) is 0.1 ng/mL. The within- and between-day variations (relative standard deviation) in the zaleplon plasma analysis are less than 2.4% (n = 15) and 4.7% (n = 15), respectively. The application of this method is demonstrated for the analysis of zeleplon plasma samples in a Phase-I human pharmacokinetic study.     

Fluorescent carbon nanoparticles: A low-temperature trypsin-assisted preparation and Fe sensing

In recent years, extensive researches are focused on the fluorescent carbon nanoparticles (CNPs) due to their excellent photochemical, biocompatible and water-soluble properties. However, these synthesis methods are generally suffered from tedious processes. In this paper, fluorescent carbon nanoparticles are synthesized by a facile, one-pot, low-temperature method with trypsin and dopamine as precursors. The synthesis process avoids any heating operation and organic solvent, which provides a “green” and effective preparation route. The obtained CNPs exhibit excellent water-solubility, salt-tolerance and photostability. Based on the synergistic action of the inner filter effect and static quenching mechanism, the CNPs are exploited as a “turn-off” fluorescence sensor for sensitive and selective detection of Fe³⁺ ions. The probe shows a wide linear range from 0.1 to 500 μM, with a limit of detection of 30 nM. Furthermore, the as-fabricated fluorescent sensing system is successfully applied to the analysis of Fe³⁺ in biological samples such as human urine and serum samples with satisfactory recoveries (92.8–113.3%).     

Convenient and Efficient Preparation of Ethyl 6-n-Decyloxy-7-ethoxy-4-hydroxyquinoline-3-carboxylate

Ethyl 6-N-decyloxy-7-ethoxy-4-hydroxyquinoline-3-carboxylate has been synthesized from pyrocatechol in six steps and in 39.3% overall yield.     

英国国家科研与创新署学科交叉研究资助机制及启示

Newly established in 2018, the UK Research and Innovation (UKRI) strengthens the strategic coordination of the UK research and innovation system by bringing together seven Research Councils, Research England, and Innovate UK. Through its nine organizations, UKRI funds multidisciplinary and interdisciplinary research in a number of priority areas. It also runs the Strategic Priorities Fund to support multidisciplinary and interdisciplinary research in strategic areas identified by government policies as well as the Global Challenges Research Fund to promote challenge-led interdisciplinary research needed by developing countries. The UKRI makes significant efforts to engage stakeholders in the development, design, and implementation of multidisciplinary and interdisciplinary programs. It has also developed a range of mechanisms to improve the evaluation of multidisciplinary and interdisciplinary projects. Chinese science and innovation funding agencies could draw upon the UKRI experience from four aspects to advance interdisciplinary research in China.     

Sorption equilibria of CO2 on silica-gels in the presence of water

The sorption equilibria of carbon dioxide on three types of silica gel (SG) with different pore size distributions in the presence of water were studied experimentally using a volumetric method at 275?K with pressures from 0 to 3.7?MPa. Both the pore size distribution of the silica gel and the quantity of pre-sorbed water impact the formation of the CO₂ hydrates. For wet silicon gel A(SG-A) with water loading ratio of 0.75, the highest CO₂ sorption was about 2.5?mmol of CO₂ per gram of dry sorbent at 275?K. Similarly, the highest sorption was about 2.7?mmol for wet SG-B with R _w =0.81. However, CO₂ hydrate did not form on the wet surface of SG-C due to its large pore sizes.     

Preparation and photoelectrochemical performance of PbSe/BaTiO3/TiO2 composite film

By dipping-lifting in sol–gel solution and reducing process, the TiO₂ composite film on the glass plate was first prepared. Then, the PbSe/BaTiO₃/TiO₂ composite film was fabricated by interface reaction with BaTiO₃ and PbSe on the surface of TiO₂ composite film. The characterization results show that the uniform porous TiO₂ film is made up of the anatase crystal, and the PbSe/BaTiO₃/TiO₂ composite film is constructed by doping or depositing BaTiO₃ and PbSe nanoparticles on the surface of TiO₂ film. The photoelectrochemical measurement results indicate that the PbSe/BaTiO₃/TiO₂ composite film has an interesting photoelectrochemical conversion property.     

Synthesis of aryloxyazetidine derivatives by CuI/l-proline catalyzed coupling reaction of arylboronic acid with 1-Boc-3-iodoazetidine

A novel CuI/l-proline catalyzed coupling reaction of 1-Boc-3-iodoazetidine with various arylboronic acids which produced aryloxyazetidine derivatives in moderate to good yields was investigated.