流动注射化学发光法测定盐酸羟苄唑

基于在碱性条件下盐酸羟苄唑能够与鲁米诺产生化学发光的现象,建立了流动注射化学发光测定盐酸羟苄唑的新方法。盐酸羟苄唑的浓度在8×10-7~1×10-4mol/L范围内与化学发光强度呈良好的线性关系,方法的(3σ)检出限为3×10-7mol/L,对1×10-5mol/L的盐酸羟苄唑连续11次测定的相对标准偏差为1.7%,回收率为96%~103%。已用于滴眼液中盐酸羟苄唑的测定。     

单层碳纳米管修饰电极上盐酸曲普利啶的电化学行为及其应用研究

应用循环伏安法研究了盐酸曲普利啶在碳纳米管修饰电极上的电化学行为.结果表明:在0.1 mol/L磷酸盐缓冲溶液(pH 6.9)中,盐酸曲普利啶产生一灵敏的氧化峰,其峰电位为0.81 V(vs.Ag/AgCl),峰电流与盐酸曲普利啶在1.0×10-6～1.3×10-4 mol/L浓度范围内呈线性关系,检出限为5.0×10-7mol/L,已用于片剂中盐酸曲普利啶的测定.     

毛细管电泳法测定白头翁汤中黄连和黄柏共煎生物碱的煎出量

 建立了利用毛细管电泳简便、准确地测定白头翁汤中黄连和黄柏共煎生物碱煎出量的方法。采用自组装毛细管电泳装置,采用75μmi.d.×50cm弹性石英毛细管,以0 05mol/LNa2B4O7 CH3OH(体积比为85∶15)溶液作缓冲液,运行电压为14kV,检测波长为232nm。另外,通过实验优化了提取溶剂中乙醇的含量。实验结果表明:以小檗碱、巴马汀提取量为指标,30%(体积分数)的乙醇水溶液是提取白头翁汤中黄连和黄柏共煎生物碱的最佳溶剂。小檗碱和巴马汀的质量浓度分别在15 0mg/L～65 0mg/L、12 5mg/L～50 0mg/L时与其峰面积有良好的线性关系;小檗碱的平均回收率不低于95%。     

Simultaneous assay of four stereoisomers of diltiazem hydrochloride. Application to in vitro chiral inversion studies

Summary The simultaneous stereospecific assay of four stereoisomers of diltiazem hydrochloride in bulk drug and aqueous solution was developed using HPLC on a Chiralcel OF column. The four isomers were quantitated with good precision by the internal standard method. The chiral inversion of (+)-cis-diltiazem hydrochloride in vitro, stability of its (2S, 3S) configuration in the solid and aqueous states was examined by HPLC. Chiral inversion of (+)-cis-diltiazem hydrochloride was not observed in the solid state, and its (2S, 3S) configuration was stable to heat, humidity and light. Chiral inversion of (+)-cis-diltiazem hydrochloride (2S, 3S) was observed in aqueous solution under UV, but not in aqueous solution stored at 80°C for 5h nor under visible light for 10 h. The (+)-cis-diltiazem hydrochloride (2S, 3S) epimerized to (+)-trans-diltiazem hydrochloride (2R, 3S) with a half-life of 5h in aqueous solution under UV but the reverse chiral inversion of (+)-trans-diltiazem hydrochloride (2R, 3S) to (+)-cis-diltiazem hydrochloride (2S, 3S) was not observed.     

Investigating the post-chemiluminescence behavior of phenothiazine medications in the luminol–potassium ferricyanide system: molecular imprinting–post-chemiluminescence method for the determination of chlorpromazine hydrochloride

A new post-chemiluminescence (PCL) phenomenon was observed when phenothiazine medications were injected into the reaction mixture after the chemiluminescence (CL) reaction of luminol and potassium ferricyanide had finished. A possible reaction mechanism was proposed based on studies of the kinetic characteristics of the CL, CL spectra, fluorescence spectra, and on other experiments. The feasibility of determining various phenothiazine medications by utilizing these PCL reactions was examined. A molecular imprinting–post-chemiluminescence (MI-PCL) method was established for the determination of chlorpromazine hydrochloride using a chlorpromazine hydrochloride-imprinted polymer (MIP) as the recognition material. The method displayed high selectivity and high sensitivity. The linear range of the method was 1.0×10⁻⁸∼1.0×10⁻⁶, with a linear correlation coefficient of 0.9985. The detection limit was 3×10⁻⁹ g/ml chlorpromazine hydrochloride, and the relative standard deviation for a 1.0×10⁻⁷ g/ml chlorpromazine hydrochloride solution was 4.0% (n=11). The method has been applied to the determination of chlorpromazine hydrochloride in urine and animal drinking water with satisfactory results.      

盐酸吡哆辛及其制剂的二阶导数差示脉冲极谱法定量研究

建立盐酸吡哆辛及其制剂的二阶导数差示脉冲极谱定量分析方法。盐酸吡哆辛在0.1mol/L氢氧化钠溶液-0.1moL/L磷酸二氢钾溶液-水(体积比为1.2:8.8:990)的混合溶液中,于-0.140V(vs·Ag/AgCl)处出现一良好的二阶导数差示脉冲极谱峰,盐酸吡哆辛浓度在3.6×10~(-4)～9.6×10~(-4)mol/L范围内与其峰幅值呈显著的线性关系(P<0.01),线性相关系数r=0.9997,检出限为9.0nmol/L。     

DSC study of cold and heat denaturation processes of β-lactoglobulin A with guanidine hydrochloride

The cold and heat denaturations of bovine P-lactoglobulin A ((β-lg A) has been studied in solutions of guanidine hydrochloride (GuHCI) by differential scanning calorimetry (DSC). The experimental results are presented and discussed. It is shown that the number of protons bound by the monomeric molecules of β-lg A was unchanged before and after its heat denaturation below pH 3, and that the activation energy of the heat denaturation was depressed owing to the presence of GuHCI. In the solutions with 2.50 and 3.06 mol/L of GuHCI, both the cold and heat denaturations of P-lg A were observed. In comparison with the heat denaturation, the activation energy of cold denaturation was far lower and the number of GuHCl molecules bound by the unfolded polypeptide chains after culd denaturation increased a lot. The absolute value of the enthalpy of cold denaturation was larger than that of heat denaturation. It was found by the analysis that the contribution to the total denaturational enthalpy of conformational change itself of the monomeric molecules of β-lg A was the lowest among the globulins, according to the average of the number of heavy atoms. Project supported by the National Natural Science Foundation of China, and by the fund for excellent items under Director of the Institute of Chemistry.     

Comparison of the Diffusion of Aqueous Glycine Hydrochloride and Aqueous Glycine

A Taylor dispersion tube has been used to measure mutual diffusion in aqueous solutions of glycine hydrochloride at 25°C and concentrations from 0.0005 to 0.5 M. Analysis of the dispersion profiles shows that the diffusion of glycine hydrochloride (GlyHCl) produces a subtantial additional flow of hydrochloric acid that is liberated by the dissociation: GlyH⁺ + Cl^- Gly + H⁺ + Cl^-. Diffusion in this system is, therefore, a ternary process described by the equations J ₁(GlyHCl) = – D ₁₁C ₁ – D ₁₂C ₂ and J ₂(HCl) = –D ₂₁C ₁ – D ₂₂C ₂ for the coupled fluxes of total glycine hydrochloride (1) and hydrochloric acid (2) components. The ratio D ₂₁/D ₁₁ of measured diffusion coefficients indicates that up to two moles of HCl are cotransported per mole of GlyHCl. Although protonated glycine diffuses with relatively mobile Cl^– counterions, the main diffusion coefficient of glycine hydrochloride, D ₁₁, is lower than or nearly identical to the diffusion coefficient of aqueous glycine. A model for the diffusion of protonated solutes is developed to interpret this result and the large coupled flows of HCl. Diffusion coefficients are also reported for the aqueous hydrochlorides of 3- and 4-aminobenzoic acids.     

非法冰毒晶体中有机杂质的气相色谱-质谱分析

建立了一种适用于分析冰毒杂质的方法,并分析其形成原因。将冰毒样品溶于1 mL 0.1 mol/L pH7.0的磷酸盐缓冲液(4份缓冲液1份10%Na2CO3),杂质用0.5 mL乙酸乙酯萃取。结果共有8种物质被检出。N-甲酰甲基安非他明、N-乙酰甲基安非他明在样品中出现,说明此批冰毒由苯丙酮(phenyl-2-propanone,P-2-P)经Leuckart法合成。N-乙基甲基安非他明的检出,则说明用于合成此批冰毒的P-2-P由苯甲醛和硝基乙烷合成。从实验结果看,该法可以满足冰毒杂质分析的需要,为分析冰毒杂质成分的成因、判断冰毒样品的合成路径提供重要信息。     

Progress on phthalocyanine-conjugated Ag and Au nanoparticles: Synthesis,characterization, and photo-physicochemical properties

Phthalocyanine (Pc) complexes are an important class of dyes with numerous (e.g., biological, photophysical, and analytical) applications. Among the methods used to improve the properties of these complexes, one should mention the introduction of different substituents, variation of the central metal ion, ligand exchange, and conjugation to nanomaterials (e.g., carbon-based nanomaterials and metal nanoparticles (NPs)). This work briefly reviews Pc complex conjugation to Ag and Au NPs, highlights the different NP shapes, and discusses the diversity of conjugation approaches. Moreover, the use of UV–Vis spectroscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, atomic force microscopy, dynamic light scattering and Fourier transform infrared spectroscopy to characterize Pc-NP hybrids is summarized. The effect of conjugation on Pc photo-physicochemical properties (fluorescence, singlet oxygen generation, triplet state formation, and optical limiting behavior) is discussed, and future perspectives for the synthesis and applications of new hybrids are provided.