曙红Y分光光度法测定阳离子表面活性剂及其机理研究

在弱酸性的HCl-NaAc缓冲介质中,阳离子表面活性剂(CS)与曙红Y(EY)染料反应,形成离子缔合物,溶液颜色发生明显改变,最大褪色波长分别在514 nm(EY-CPB体系)、516 nm(EY-CTAB体系),同时在548 nm(CPB体系)、544 nm(CTAB体系)处有吸收峰,在褪色波长处阳离子表面活性剂的浓度与褪色程度呈良好线性关系,从而建立测定阳离子表面活性剂的光度法。在最大褪色波长处,CPB体系、CTAB体系中CS的浓度在0~4.79×10-5mol/L、0~2.90×10-5mol/L范围内遵守比尔定律,表观摩尔吸光系数为2.94×104、2.86×104L.mol-1.cm-1,检出限为8.97×10-7mol/L、7.87×10-7mol/L。若用双波长叠加,表观摩尔吸光系数达5.58×104、5.20×104L.mol-1.cm-1,检出限为5.87×10-7、6.25×10-7mol/L。方法适用于水样中CS的测定。本文还用密度泛函理论对反应机理进行了探讨。     

溴甲酚紫、溴甲酚绿光度法测定阿昔洛韦

在pH 3.30的NH2CH2COOH-NaCl-HCl缓冲介质中,阿昔洛韦(Aciclovir,ACV)可与溴甲酚紫(BCP)、溴甲酚绿(BCG)反应,形成离子缔合物,溶液颜色发生明显变化,其最大褪色波长分别为428 nm(BCP-ACV)、450 nm(BCG-ACV),在此波长处,阿昔洛韦的浓度与溶液褪色程度呈良好线性关系,可用分光光度法测定。在BCP-ACV、BCG-ACV体系的最大褪色波长处,ACV的浓度分别在0~2.69×10-5mol/L、0~2.58×10-5mol/L范围内遵守比耳定律,表观摩尔吸光系数分别为2.53×104L.mol-1.cm-1、1.79×104L.mol-1.cm-1,检出限分别为5.10×10-7mol/L、7.13×10-7mol/L。方法用于药品、血浆及尿液中阿昔洛韦的测定,结果满意。     

阻抑褪色光度法测定水样中阴离子表面活性剂

在弱酸性的HCl-NaOAC缓冲介质中,溴化十六烷基吡啶(CPB)和曙红Y(EY)染料的混合溶液发生褪色,在该褪色的溶液中分别加入十二烷基硫酸钠(SDS)及十二烷基苯磺酸钠(SDBS)等阴离子表面活性剂(AS),溶液颜色发生改变,最大吸收波长都在514 nm处,并分别在548、546 nm处产生明显褪色。在吸收或褪色波长处,阴离子表面活性剂的浓度与增色或褪色程度呈良好线性关系,从而建立测定阴离子表面活性剂的光度法。在最大吸收波长处,SDBS体系、SDS体系中AS的浓度在0~2.06×10-5mol/L、0~2.63×10-5mol/L范围内遵守比尔定律,表观摩尔吸光系数分别为1.30×104、1.01×104L.mol-1.cm-1,检出限分别为8.14×10-7、9.96×10-7mol/L。若用双波长叠加,表观摩尔吸光系数达2.07×104、1.78×104L.mol-1.cm-1,检出限为4.82×10-7、8.34×10-7mol/L。方法具有较高的灵敏度和良好的选择性,用于水样中AS的测定。     

用刚果红分光光度法测定阳离子表面活性剂

在弱酸性的HCl-NaAc缓冲介质中,某些阳离子表面活性剂(CS)与刚果红(CR)反应,形成离子缔合物时,刚果红发生褪色作用,最大褪色波长分别在510nm(CR-溴化十六烷基吡啶(CPB)体系)、514nm(CR-十六烷基三甲基溴化铵(CTAB)体系)。在最大褪色波长处,CS的浓度在0~4.16×10-5mol.L-1(CPB体系)、0~3.18×10-5mol.L-1(CTAB体系)范围内遵守比尔定律,表观摩尔吸光系数为1.62×104L/(mol.cm)(CPB体系)、1.72×104L/(mol.cm)(CTAB体系),检出限为9.78×10-7mol.L-1(CPB体系)、1.04×10-6mol.L-1(CTAB体系)。方法具有较高的灵敏度和良好的选择性,用于水样中CS的测定,结果满意。     

依文思蓝光度法测定阿昔洛韦及其分析应用

在pH 5.74 HAc-NaAc缓冲介质中, 阿昔洛韦(ACV)与依文思蓝(EB)反应形成离子缔合物, 溶液颜色发生明显改变, 最大褪色波长为638 nm. 在此波长处, 阿昔洛韦的浓度与褪色程度呈良好线性关系, 从而建立测定阿昔洛韦的光度法. 在最大褪色波长处, 阿昔洛韦的浓度在0～2.01×10-5 mol/L范围内遵守比尔定律, 表观摩尔吸光系数1.71×104 L·mol-1·cm-1, 检出限为7.47×10-7 mol/L. 方法具有较高的灵敏度和良好的选择性, 可用于实际药品、血浆及尿液中阿昔洛韦的测定.     

氨基黑10B褪色光度法测定两种阳离子表面活性剂及其作用机理

在弱酸性的乙酸盐介质中,阳离子表面活性剂(CS)与氨基黑10B(AB)染料反应,形成离子缔合物,溶液颜色发生明显褪色,最大吸收在616 nm,CS的浓度在0~2.17×10-5mol.L-1(CPB)、0~2.09×10-5mol.L-1(CTMAB)范围内遵守比耳定律,表观摩尔吸光系数为2.16×104L.mol-1.cm-1(CPB)、1.93×104L.mol-1.cm-1)(CTMAB),检出限为7.64×10-7mol.L-1(CPB)、1.31×10-6mol.L-1(CTMAB)。用于水样中CS的测定,还用密度泛函理论对反应机理进行了探讨,结果与试验事实相符合。     

乙基曙红-溴化十六烷基吡啶光度法测定水样中阴离子表面活性剂

在弱酸性的HAC-NaAC缓冲介质中,将溴化十六烷基吡啶(CPB)与乙基曙红(EE)染料溶液混合,加入阴离子表面活性剂(AS),溶液颜色加深,最大吸收波长都在516nm处,且阴离子表面活性剂的浓度与溶液的增色程度呈良好线性关系。在最大吸收波长处,3种阴离子表面活性剂——十二烷基苯磺酸钠(SDBS)、十二烷基磺酸钠(SLS)及十二烷基硫酸钠(SDS)的浓度分别在0~2.05×10-5mol/L、0~2.08×10-5mol/L、0~2.04×10-5mol/L范围内遵守比尔定律,表观摩尔吸光系数分别为2.38×104、2.82×104和2.98×104L/(mol.cm),检出限分别为8.42×10-7、4.56×10-7和7.95×10-7mol/L。方法具有较高的灵敏度和良好的选择性,用于不同水样中AS的测定,结果满意。     

应用刚果红-壳聚糖褪色反应光度法测定微量阳离子表面活性剂

在pH 10.5的B-R(或pH 9.0的氨水-氯化铵)缓冲溶液中,溴化十六烷基三甲胺和氯化十六烷基吡啶能使刚果红与壳聚糖(体系Ⅰ)或刚果红与羧甲基壳聚糖(体系Ⅱ)生成的有色物质产生灵敏的褪色反应,在530 nm波长处,其褪色程度△A与溴化十六烷基三甲胺及氯化十六烷基吡啶用量呈线性关系,溴化十六烷基三甲胺和氯化十六烷基吡啶的质量浓度分别在0.2～3.6 mg·L-1(体系Ⅰ)和0.08～3.2 mg·L-1(体系Ⅱ)范围内呈线性,表观摩尔吸光率εCTMAB=2.08×104L·mol-1·cm-1,εCPC=2.52×104L·mol-1·cm-1(体系Ⅰ);εCTMAB=2.22×104L·mol-1·cm-1,εCPC=2.55×104L·mol-1·cm-1(体系Ⅱ),拟定的方法用于水样中微量阳离子表面活性剂的测定,测得方法的回收率在99.1%～100.8%之间,测定值的相对标准偏差(n=6)在1.2%～3.0%之间.     

新试剂4,4′-(2-氯-4-硝基重氮氨基)联苯与氯化十六烷基吡啶显色反应的研究

研究了4,4′-(2-氯-4-硝基重氮氨基)联苯与阳离子表面活性剂氯化十六烷基吡啶发生显色反应,提出了光度法测定氯化十六烷基吡啶的新方法。实验结果表明,在碱性介质中,4,4′-(2-氯-4-硝基重氮氨基)联苯与氯化十六烷基吡啶形成1∶2紫红色离子缔合物,最大吸收波长位于570 nm处,表观摩尔吸光系数为2.16×104L·mol-1.cm-1。表面活性剂的浓度在0～3.0×10-5mol/L范围内符合比耳定律。方法可直接应用于合成水样中阳离子表面活性剂的测定。     

刚果红褪色光度法测定盐酸西布曲明及作用机理研究

在弱酸性NaH_2PO_4-Na_2HPO_4的缓冲介质中,盐酸西布曲明与刚果红染料反应,形成离子缔合物,溶液颜色发生明显改变,褪色波长在342nm、490nm,其中最大褪色波长在490nm,从而建立了测定盐酸西布曲明的光度法。在最大褪色波长处,盐酸西布曲明的浓度在0.35~3.2×10-5mol/L范围内遵守比尔定律;表观摩尔吸光系数ε490为1.67×104L·mol-1·cm-1;检出限为4.45×10-7mol/L。方法具有较高的灵敏度和良好的选择性,用于曲美胶囊中盐酸西布曲明的测定,结果满意。本实验还用密度泛函理论对反应机理进行了探讨,结果与实验结果相符合。     

The effect of alkyltrimethylammonium bromides on the thermal stability of dioctadecyldimethylammonium bromide (DOAB) vesicles in aqueous solutions

The influence of alkyl chain length in alkyltrimethylammonium bromides on the gel to liquid crystal transitions in DOAB versicles is examined using differential scanning microcalorimetric data. The changes in melting temperature, patch number and standard enthalpy of melting for DOAB vesicles depend strongly on added surfactants and their concentration. The data show that vesicles are readily penetrated by surfactant molecules when the vesicles are in the liquid crystal state and the penetration is facile when the length of alkyl chains in both surfactants and vesicles are comparable. Furthermore, the vesicles are made up of domains that differ in composition.     

On the adsorption and condensed film formation of binary mixtures of dodecyl-, tetradecyl-, hexadecyl-, and octadecyl-trimethylammonium bromides at the mercury–electrolyte interface

The adsorption and condensed film formation on mercury at the negative potential region for binary mixtures of dodecyltrimethylammonium bromide (DTAB), tetradecyltrimethylammonium bromide (TTAB), cetyltrimethylammonium bromide (CTAB), octadecyltrimethylammonium bromide (OTAB) is studied in KBr at various temperatures from 5 to 45 °C. The formation of the CTAB condensed film is hindered with the addition of DTAB and TTAB. There are interactions between unlike hydrophobic chains. The strong interactions between the CTAB molecules do not take place when DTAB or TTAB is present above a certain concentration. This hindering is more pronounced in the case of TTAB compared to the same DTAB concentration, i.e. the increase of the chain length hinders the film formation. The initially adsorbed molecules play a templating role in the kinetics of the film formation and in the self-assembling of the molecules. The initial induction time strongly depends on the temperature. The less surface active CTAB can hinder the OTAB film formation in binary mixtures. Also, increased interaction between OTAB and CTAB can be observed, indicating synergy effects in the film formation in some cases. The temperature range that the film is formed can be changed using mixtures of surfactants. Thus, the development of the film can become impossible, more difficult or even easier. Hysteresis phenomena are observed. The capacity versus time curves in the case that condensed film is formed are treated with the Avrami plot formulation, giving values between 1.5 and 2 indicating a progressive one dimensional nucleation with constant growth rate or a decrease of the nucleation rate during the overall film formation. There is generally a marked effect of the chain length of the alkyl chain on the film formation.     

Viscosities of aqueous solutions of quaternary phosphonium bromides at 15, 25 and 35°C

The viscosities of aqueous solutions of Bu _4-n Ph _n PBr n=0–4 have been measured over the concentration range 0.01–0.2 M at 15, 25 and 35°C, to examine the differences in ion-water interactions of these quaternary cations. The viscosity data were treated by the extended Jones-Dole equation, including the square term in solute concentration, Dc². A decrease in the B coefficient with increase in the number of phenyl groups n, and with increasing temperature is observed. Nearly linear dependence of the B coefficient on n was found, in contrast with partial molal volumes for which non-linear relations with n have been found. D decreases with increasing temperature but becomes independent of n at higher temperatures.     

Spectrophotometric determination of bromide

A Spectrophotometric method for bromide determination has been developed. Bromide is converted to tribromide which absorbs at 267 nm. The detection limit is 0.01 g/ml bromide. As little as 0.4 g of bromide can be determined in an excess of chloride and sulfate with a coefficient of variation of 4%.     

DSC Investigations of DDAB,DTAB and DHAB Vesicle Aqueous Solutions in Presence of SDS

Interactions of anionic surfactant sodium dodecyl sulphate (SDS) with vesicles formed by synthetic dialkyldimethylammonium bromides i.e. didodecyldimethylammonium bromide (DDAB), ditetradecyldimethylammonium bromide (DTAB), dihexadecyldimethylammonium bromide (DHAB) have been examined by using differential scanning microcalorimetry and electron transmission microscopy. The temperatures and standard enthalpies characterising gel to liquid-crystal transitions increase significantly with increase of SDS concentration for all investigated systems. It means that incorporation of SDS monomers in these vesicular bilayers significantly stabilises their gel states. Moreover, in case of DDAB and DTAB vesicle systems added SDS limits kinetic features of recorded isobaric heat capacity dependencies on temperature observed earlier for the pure vesicular solutions. This revised version was published online in July 2006 with corrections to the Cover Date.     

亮绿褪色反应用于微量季铵盐型阳离子表面活性剂的分光光度法测定研究

在 p H 7.0 0 Tris- HCl缓冲介质中 ,微量季铵盐型阳离子表面活性剂溴化十六烷基三甲胺 ( CTMAB)和溴化十六烷基吡啶 ( CPB)能使亮绿 ( Brilliant Green,简称 BG)产生灵敏的褪色反应 ,发现其褪色程度ΔA (ΔA =A0 - Ai)与 CTMAB及 CPB用量存在定量关系。研究了该褪色反应的最佳条件 ,探讨了反应机理 ,拟定了利用该反应用于微量 CTMAB和 CPB的测定方法 ,CTMAB和 CPB的浓度分别在0～ 6× 1 0 - 5mol/ L ,0～ 8× 1 0 - 5mol/ L范围内符合比耳定律。拟定的方法用于电镀废液样品中微量 CTMAB的测定 ,结果满意     

Photorearrangement of Propargyl Bromide as a Probe to Study Propargylic and Allenic Radicals by Infrared Matrix Isolation Technique

The photolysis of propargyl bromide in Ar matrix to form allenyl bromide proceeded with a radical mechanism. The deuterium label study and radical scavenger were used to investigate the mechanism. Neither propargyl nor allenyl radical was trapped in Ar matrix at 8 K. The rates of propargyl and allenyl radicals coupled with bromo radical are significantly fast. The stability of propargyl and allenyl radicals is discussed.     

Simple and Efficient Method for Obtaining Fluorene and Spirobifluorene Bromide Derivatives

A mild, simple, and efficient synthetic procedure for the preparation of 2-monobromo-, 2,7-dibromo-, and 2,2′,7,7′-tetrabromo-substituted spirobifluorene derivatives and their key intermediates, 2-monobromo- and 2,7-dibromo-substituted fluorene compounds, has been developed. The oxidative bromination of fluorene and spirobifluorene was achieved using NaBr/H₂O₂ as the bromine source. High conversion of the starting materials was achieved together with good selectivities under optimized reaction conditions.     

二甲基烯丙基胺/溴代烷烃系列季铵盐的合成与表征

以溴代烷与二甲基烯丙基胺(DMAA)为原料合成了二甲基烯丙基类季铵盐;探讨了反应温度、原料配比、反应时间及溶剂对反应产率的影响,确定了最佳合成条件;并采用红外光谱仪、核磁共振谱仪(1 H NMR)及质谱仪表征了产物的结构.     

Apparent molal volumes of phosphonium halides at 15, 25 and 35°C

The densities of aqueous solutions of the phosphonium halides, Bu _4-n Ph _n PX(n=0–4), some of which were synthesized from the phosphines, were measured at 15, 25 and 35°C. Partial molal volumes at infinite dilution, , and B _v coefficients for the apparent molal volumes were determined at each temperature. For the first four cations varies little with n. For all salts B _v are negative but become less negative with increasing n. The temperature dependence of B _v is positive for butyl-rich salts (n<2) but negative for phenyl-rich salts (n>1). Also it appears that is relatively large for phenyl-rich cations in comparison with that for butyl-rich cations.