流动注射抑制化学发光法测定间苯二酚

基于碱性介质中间苯二酚抑制鲁米诺高碘酸钾单宁体系的化学发光,建立了反相流动注射抑制化学发光测定间苯二酚的新方法.该方法快速、准确、线性范围宽,测定间苯二酚的检出限为3.6×10-5g/L,方法的线性范围为8.0×10-5~4.0×10-3g/L,对于2.0mg/L间苯二酚测定11次的相对标准偏差为0.87%.应用于皮炎宁酊中间苯二酚的测定,结果令人满意.     

杯[4]间苯二酚对-5,11,17,23-四苯偶氮磺酸盐的合成

间苯二酚与正丁醛反应得到杯[4]间苯二酚(1)，1与对苯磺酸偶氮盐反应得到正丁醛杯[4]间苯二酚对-5，11，17，23-四苯偶氮磺酸盐(2)，2的结构经过IR，UV，^1H NMR，MS谱图确认。考察了pH值和溶剂对2的紫外吸收光谱及其与Ag(Ⅰ)的显色反应的影响。     

Syntheses of antimony(v) derivatives from trimethyl and triphenylantimony(III), dihydric phenols,andtert-butyl hydroperoxide

Trimethyl and triphenylantimonyo-phenylene dioxides were obtained by the reaction of trimethyl- and triphenylantimony with pyrocatechol in the presence oftert-butyl hydroperoxide in 68 and 81 % yields, respectively. 7,7,7,15,15,15-Hexamethyl-(and phenyl)-6,8,14,16-tetraoxa-7, 15-distibatricyclo[11.3.1.1^9,13]octadeca-1,3,5,9,11,13-hexaenes were synthesized analogously by the reaction with resorcinol (in 79 and 93 % yields, respectively). The use of hydroquinone resulted in polymeric trimethyl- and triphenylantimony hydroquinolates.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 748–751, April, 1995.This work was carried out with financial support from the Russian Foundation for Basic Research (Project No 94-03-08846).     

Multiwavelength spectrophotometric determination of protolytic constants of 4-(2-pyridylazo) resorcinol (PAR) in binary DMF-water mixtures

A multiwavelength spectrophotometric titration method was applied to study the protolytic constants of 4-(2-pyridylazo) resorcinol(PAR), in binary DMF + water mixtures. UV-vis absorption spectra of PAR solution were recorded in the course of pH-metric titration of acidic solutions of PAR with standard base solution. The protolytic equilibrium constants, spectral profiles, concentration diagrams and also the number of components have been calculated from the fitting of the pH-spectral titration data with appropriate mass balance equations by a home written program according to an established target factor analysis. To precise determination of number of absorptive components a recently developed statistical indicator function (IND function) was used. A glass electrode calibration procedure based on a four-parameter equation pH=α+SpcH+JH⁺[H⁺]+JOH⁻Kw/[H⁺] based on the Gran's plots was used to obtain pH readings in the concentration scale (p_cH). It has been observed that there is an inverse relationship between second and third protolytic constants and mole fraction of DMF. The effect of the solvent on the protolytic constants was discussed.     

痕量间苯二酚的B-Z振荡反应动力学测定

研究了在封闭体系中B Z振荡反应测定间苯二酚的条件 ,建立了测定痕量间苯二酚的新方法 .当 [KBrO3]=0 2 5mol/L ,[CH2 (COOH) 2 ]=0 5mol/L ,[Ce(SO4 ) 2 ]=0 0 4mol/L ,[H2 SO4 ]=0 8mol/L时 ,间苯二酚在 6 5×10 - 7mol/L～ 1 0× 10 - 5mol/L范围内 ,浓度与振幅改变值ΔA呈线性关系 ,检出限为 6 0× 10 - 7mol/L .用于废水中间苯二酚的测定 ,回收率为 99% .     

Release and extraction of letrozole in blood plasma using resorcinol functionalized multi-walled carbon nanotube coupled with high-performance liquid chromatography

In this research, carboxylated multi-walled carbon nanotube was functionalized by cyanuric chloride and modified by 1,3 dihydroxybenzene (MWCNT-resorcinol). MWCNT-resorcinol was used as an adsorbent for extraction and determination of letrozole in human blood plasma prior to high-performance liquid chromatography equipped with ultraviolet detector (HPLC-UV). Synthesized carbon nanotubes were modified and characterized using Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The efficiency of the adsorbent for adsorption and release of letrozole in the blood plasma was evaluated at the optimized condition. An adsorption efficiency of 96.9% was achieved at pH of 4 and the extraction time of 20?min. A recovery percentage of 92.7% for the drug in plasma was also obtained. Lastly, the release efficiency values for letrozole from MWCNTs-resorcinol in simulated gastric fluid (pH 1.2) and simulated intestinal fluid (pH 7.4) were calculated as 91% and 70%, respectively. Such results enhanced the potential ability of the MWCNTs-resorcinol as a drug delivery substrate.     

锰与4-(2-噻唑偶氮)间苯二酚络合吸附波的研究及应用

本文研究了在0.01mol/L NaOH—0.32％乙二胺—0.05mol/L酒石酸钾钠介质中,锰与4-(2-噻唑偶氮)间苯二酚(TAR)络合吸附波的极谱行为。当介质中含有0.003％TAR时,Mn会产生灵敏的导数极谱波,其峰电位为-0.75V(相对银汞齐电极,下同),方法检出限为1.5×10~(-9)mol/L,线性范围为3.6×1.0~(-9)mol/L～2.7×10~(-6)mol/L。研究了极谱波的性质、机理以及络合物的组成。方法成功地应用于某些植物叶中微量锰的含量测定。     

Determination of Nb(V), V(V), Co(II), Fe(III), Ni(II), Ru(III) and Pd(II) as their 4-(5-nitro-2-pyridylazo) resorcinol chelates by reversed-phase high performance liquid chromatography

This paper reports the separation and determination of Nb(V), V(V), Co(II), Fe(III), Ni(II), Ru(III) and Pd(II) by reversed-phase HPLC using the new reagent, 4-(5-nitro-2-pyridylazo) resorcinol (5-NO₂-PAR) as a precolumn derivatization reagent. On a C₁₈ column, the seven metal chelates can be separated quantitatively with methanol/water (5248, v/v) containing 15 mmol/l pH 5.0 acetate buffer and 10 mmol/l tetrabutylammonium bromide (TBA·Br). The detection limits for Nb(V), V(V), Co(II), Fe(III), Ni(II), Ru(III) and Pd(II) are 0.65 ppb, 0.94 ppb, 0.10 ppb, 0.15 ppb, 0.18 ppb, 3.02 ppb and 2.35 ppb, respectively when the ratio of signal to noise (S/N) is 3. This method is simple and rapid, and has been used in the analysis of rain and liquor with satisfactory results.     

New symmetric azobenzene molecules of varied central cores: Synthesis and characterisation for liquid crystalline properties

A new series of azobenezene liquid crystals (LCs) was designed and synthesised by known and straightforward methods. The central connecting cores of the molecules varied viz., benzene/naphthalene/biphenyl. The molecular structures were confirmed by infrared, UV, nuclear magnetic resonance spectroscopic techniques. The LC texture and thermal phase behaviours were investigated by polarising optical microscopy and differential scanning calorimetry. Smectic B phase was found in biphenyl-derived azobenzene ester. The effect of central core on LC properties was investigated. The decreased angle at central connecting core suppressed the melting points, phase transition temperatures without losing LC properties, whereas, in moderate angle compounds LC properties were suppressed. The compounds with increased angle at central core favours rich mesomorphism.