反相高效液相色谱法同时测定苦豆子及其制剂中苦参碱和氧化苦参碱

建立了用反相高效液相色谱法测定苦豆子及其制剂中苦参碱和氧化苦参碱的方法。色谱条件：ＯＤＳ柱，甲醇－水－三乙胺，φ（甲醇）＝０．５５，φ（三乙胺）＝０．０００２为流动相，紫外检测波长２１５ｍｍ。为苦豆子及共制剂的质量评价提供了一种方法     

反相高效液相色谱法测定三种中药中粉防己碱

本文首次用反相高效相色谱法分离并测定了粉防己，头花千金藤，蝙蝠葛三种中药中的粉防己碱，建立了中粉防己碱分离，测定了色谱方法，色谱条件：ＯＤＳ柱，甲醇－水－三乙胺（８５：１５：０．２５Ｖ／Ｖ）为流动相，紫外检测器测波长２８３ｎｍ。本研究的扩大中药及植物中粉防己碱药物资源的开发提供了简便，灵敏，准确的分离，测定方法。     

反相高效液相色谱法同时测定苦豆子及其制剂中苦参碱和氧化苦参碱

建立了用反相高效液相色谱法测定苦豆子及其制剂中苦参碱和氧化苦参碱的方法。为苦豆子及其制剂的质量评价提供了一种方法。     

手性1,3,4-噁二唑硫醚衍生物的合成

以5-取代-2-巯基-1,3,4-噁二唑为亲核试剂,与手性5-烷氧基-3,4-二溴-2(5H)-呋喃酮发生Michael反应,合成了6种新的手性1,3,4-噁二唑硫醚衍生物(产率55%～67%),其结构经1H NMR, 13C NMR, IR和HR-MS确证.     

反相高效液相色谱法测定狼把草中的木犀草素

胜反相高效液相色谱法分离并测定了狼把草中的木犀草素，建立了该中药中木犀草素分离，测定的色谱方法。     

Determination of trace europium(III) based on a new fluorescence enhancement system of europium(III) with N,N′-<Emphasis Type="Italic">bis</Emphasis>-(4-N-aminothiourea-2-amylidene)-4,4′-diaminodiphenyl sulfone by EDTA or alumin in N,N-dimethylformamide

A new bis-Schiff base ligand, N,N-bis-(4-N-aminothiourea-2-amylidene)-4,4-diaminodiphenyl sulfone (ARADS), was synthesized. The solutions of its complex with Eu³⁺ in DMF can emit the intrinsic fluorescence of Eu³⁺. The fluorescence intensity of the complex was enhanced 20–30-fold in the presence of EDTA (or alum). The influence of seven kinds of solvents (DMF, CH₃CN, THF, acetone, CH₃OH, C₂H₅OH, and DMSO) on the intensity of fluorescence was studied. The results showed that the Eu³⁺-ARADS-EDTA (or alum) system emits its strongest fluorescence in DMF. Thus, the system can be used to develop a new method for the determination of europium(III). The excitation and emission wavelengths are 395 and 615 nm, respectively. Under optimal conditions, the fluorescence intensities vary linearly with the concentration of Eu³⁺ in the range 6.0 × 10^–10–5.2 × 10^–5 mol/L, with a detection limit of 5.0 × 10^–10 mol/L. The interference from some rare earth metals and other inorganic ions are described. The method is a selective, sensitive, rapid, and simple analytical procedure for the determination of europium(III) in high-purity yttrium oxide and synthetic samples. The mechanism of fluorescence enhancement was also studied.__________From Zhurnal Analiticheskoi Khimii, Vol. 60, No. 4, 2005, pp. 372–377.Original English Text Copyright © 2005 by Tianlin Yang, Wenwu Qin, and Weisheng Liu.The article was submitted by the authors in English.     

Recent Progress on Bismuth-based Nanomaterials for Electrocatalytic Carbon Dioxide Reduction

Due to the burning of fossil fuels, the level of carbon dioxide(CO₂) in the atmosphere gradually rises, leading to serious greenhouse effect and environmental problems. Electrocatalytic reduction of CO₂ is currently an efficient way to convert CO₂ to value-added products. Bismuth(Bi)-based nanomaterials have raised great interests due to their excellent activity and high selectivity to electrocatalytic CO₂ reduction. In this review, the fundamental principles of electrochemical CO₂ reduction reaction(CO₂RR) are introduced at first. Moreover, the recent development of Bi-based electrocatalytic materials including Bi with various nanostructures(nanoparticle, nanosheet, etc.), Bi-based compounds(Bi oxide, bimetal chalcogenide, etc.), and Bi/C nanocomposites are summarized. In the end, the future prospects and challenges of electrocatalysts for CO₂ reduction are discussed.     

Composite of Pt–Ru supported SnO2 nanowires grown on carbon paper for electrocatalytic oxidation of methanol

Platinum–ruthenium (Pt–Ru) nanoparticles were successfully deposited, for the first time, on the surface of SnO₂ nanowires grown directly on carbon paper (Pt–Ru/SnO₂ NWs/carbon paper) by potentiostatic electrodeposition method. The resultant Pt–Ru/SnO₂ NWs/carbon paper composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The electrocatalytic activities of these composite electrodes for methanol oxidation were investigated and higher mass and specific activities in methanol oxidation were exhibited as compared to Pt–Ru catalysts deposited on glassy carbon electrode.     

Vapor Pressure Osmometry and Its Applications in the Osmotic Coefficients Determination of the Aqueous Monomer Glycol and Polymer Polyethylene Glycol Solutions at Various Temperature

Based on the principle and calibration of vapor pressure osmometer and its application in the thermodynamics of the aqueous solutions, the results on aqueous solution of monomer glycol,PEG200,PEG400,PEG1500 and PEG2000 over the different concentration range at various temperatures were reported.Using a linear least-square fitting routing,the osmotic coefficients were fitted by a simple polynomial equation.It was found that the relationship between the molar osmotic coefficients (Φ） and the molar concentration(c) of the solutions are in a quite good agreement with the fitted polynomial equation at various temperatures over the different concentration range.The experimental results also show that over the studied concentration range and at various temperatures,the concentration dependence of the molar osmotic coefficients of the aqueous solution systems with the solutes of PEG200,PEG400,PEG1500 and PEG2000 are totally presented in a rising tend,and their temperature dependence of the osmotic coefficients of the aqueous solution systems of the molar concentration exhibits their own regularities,respectively.The aqueous glycol solution system exhibits the properties of the dilute solution.     

ICP-OES determination of traces of Ru, Au, V and Ti preconcentrated and separated by a new poly(epoxy-melamine) chelating resin from solutions

A new poly(epoxy-melamine) chelating resin is synthesized from epoxy resin and used for the preconcentration and separation of traces of Ru(III), Au(III), V(V) and Ti(IV) ions from sample solutions. The ions analyzed can be quantitatively enriched by the resin at a flow-rate of 2 mL/min at pH 4, and quantitatively desorbed with 10 mL of 1 mol/L HCl + 0.2 g CS(NH₂)₂ at a flow-rate of 1 mL/min with recoveries of over 97%. The chelating resin can be reused 7 times without obvious loss of efficiency. Thousand-fold excesses of coexistent ions caused little interference during the enrichment and determination steps. The RSDs for the determination of 50 ng/mL Ru(III) and Au(III), 5.0 ng/mL V(V) and Ti(IV) were in the range of 1.5–4.5%. The recoveries of added standards in a real sample solution are between 96% and 100%, and the results for the ions analyzed in a nickel alloy sample are in good agreement with their reported values.