TOMAC/正辛醇/异辛烷反胶团体系

研究了用三辛基甲基氯化铵(TOMAC)/正辛醇/异辛烷反胶团相转移法萃取细胞色素C时,水相pH值、离子强度、正辛醇含量、相体积比、搅拌时间等因素的影响.结果表明,正辛醇的量、水相pH值是萃取过程的关键因素,在低离子强度(CKCl＝0.05*!mol/L)、高pH值(pH＝13.66)、含正辛醇体积分数为0.85%的情况下,萃取率接近100%.     

TOMAC／正辛醇／异辛烷反胶团体系萃取细胞色素C

研究了用三辛基甲基氯化铵（TOMAC）／正辛醇／异辛烷反胶团相转移法萃取细胞色素C时,水相pH值、离子强度、正辛醇含量、相体积比、搅拌时间等因素的影响。结果表明,正辛醇的量、水相pH值是萃取过程的关键因素,在低离子强度（CKCl＝0．05mol/L）、高pH值（pH＝13．66）、含正辛醇体积分数为0．85％的情况下,萃取率接近100％。     

反胶团萃取分离纯化色氨酸

色氨酸是人体内的必需氨基酸之一。针对色氨酸的分离纯化,提出一种基于CTAB为表面活性剂的反胶团法分离纯化方法。结果表明,CTAB浓度为40mol／L;以正丁醇作为有机溶剂;异辛烷作为助表面活性剂,二者之比为1：1（V：V）;萃取PH为12;萃取离子选择氯化钾;萃取浓度为0．3mol／L;反萃PH为4;反萃离子为氯化钾;萃取浓度为2mol／L,萃取时间为15min;水浴振荡250r／min;反萃时间为20min;水浴振荡250r／min;萃取温度为室温;回收率最高可以达到60％左右。     

微乳液法制备纳米羟基磷灰石的机理

采用二已基琥珀酰磺酸钠(aerosol OT,AOT)作为表面活性剂,正辛醇作为助表面活性剂,异辛烷为油相,将Ca(H2PO4)2·H2O水溶液和Ca(OH)2饱和溶液作为水相制成反相微乳液,并使两种微乳液反应,制备出呈单分散的球形纳米羟基磷灰石颗粒.通过系统性试验绘制了AOT/异辛烷/Ca(H2PO4)2·H2O水溶液和AOT/异辛烷/Ca(OH)2饱和溶液微乳液的局部三元拟相图,确定了该体系的反相微乳液单相区.采用动态激光散射原理分析了上述微乳液的胶束直径,确定了胶束直径与体系含水量的线性关系,并计算了微乳液胶束的有关参数.分析了羟基磷灰石的反应机理和颗粒的形成过程,并采用紫外可见光吸收光谱,研究了体系含水量对羟基磷灰石超细颗粒形成过程的影响.     

反胶团酶膜反应器研究进展

两亲分子溶入有机溶剂时可自组织形成球形聚集体，称作反胶团，酶能溶入反胶团的水池中以催化特定的反应文中对反胶团介质中的酶反应进行了介绍，并对膜反应器在反胶团酶反应中的应用进行了综述     

DBC与MSO从碱性氰化液中协同萃取金的研究

研究了在用DBC,MSO及DBC-MSO作萃取剂的碱性氰化液中萃取Au(Ⅰ)的性能.考察了萃取剂和助萃剂的浓度、相比、萃取时间等因素对Au(Ⅰ)萃取率的影响以及Na2S2O3反萃金的性能.实验表明,在采用某种助萃剂X助的作用下,DBC-MSO体系从碱性氰化液中萃取金的协萃效应较高.在整个组成范围内,协萃系数R均大于1.助萃剂X助对DBC-MSO体系萃金的影响较大,但X助本身不萃金.DBC-MSO体系能快速萃取金,在1 min内已基本达到萃取平衡.DBC-MSO协萃体系有望能成为碱性氰化液中萃取金的一项新技术.     

支撑液膜提取柠檬酸的传质机理

研究和探讨柠檬酸提取的化学过程,论述了反萃取剂Na2CO3与溶质柠檬酸的最终化学计量比并非是化学反应比3∶2而是1∶1,甚至更低,也就是说,在反萃取相中不仅存在C6H5O73-,而且存在HC6H5O72-或H2C6H5O7-.提高反萃取剂的浓度对溶质提取有利.为深入研究该技术提供了理论依据.     

以HDEHP为载体的大块液膜迁移铕离子动力学研究

以二 (2 -乙基己基 )磷酸 (HDEHP)为载体 ,考察了搅拌速度、温度、石蜡及表面活性剂对大块液膜迁移铕离子的影响 ,获得了各种实验条件下的表观反应速率常数 ,萃取和反萃取的表观反应活化能分别为 1 0 .7kJ/mol和 2 9.2kJ/mol.结果表明 ,萃取过程扩散为控速步骤 ,反萃取过程化学反应亦为控速步骤 ,Eu(Ⅲ )离子的跨膜迁移过程可以以两个串联的准一级不可逆过程进行描述 .     

钽铌萃取残液中钛的回收

钛钽铌矿经湿法冶炼提取Ta、Nb后,其萃取残液含Ti.对这一工业废液中Ti回收工艺进行研究.结果表明:以含Ti萃取残液和KCl为原料,用仲莘醇 HCl除Fe、NaCl除Si,制得粗K2TiF6(含Na2TiF6杂质),经重结晶得到K2TiF6产品.粗K2TiF6经水溶、氨沉、调洗、烘干得到H2TiO3的富集物,富集物经煅烧得到TiO2产品.从Ta、Nb的萃取残液到K2TiF6产品,Ti的直收率(以TiO2计)达到89%;从萃取残液到TiO2产品,Ti的直收率(以TiO2计)达到76%.     

2-氨基-5-巯基-1,3,4-噻二唑对青铜文物的缓蚀性能及密度泛函理论分析

采用失重法和电化学测试技术研究了2-氨基-5-巯基-1,3,4-噻二唑(AMT)作为青铜文物缓蚀剂的缓蚀效率。失重实验结果表明,在25℃、1.0×10~(3 )mmol/L的H_2SO_4和柠檬酸溶液中加入AMT后,当缓蚀剂浓度达到5.0mmol/L时,缓蚀效率可达100%。电化学分析结果表明,在28.0mmol/L NaCl+10.0mmol/L Na_2SO_4+16.0 mmol/L NaHCO_3组成的混合溶液中,当AMT的浓度达到1.0mmol/L后,缓蚀效率达到92.76%,腐蚀电流密度下降到4.71μA/cm~2。量化计算结果表明,缓蚀剂AMT分子上的活性中心主要分布在S7、S3和N6原子上,并利用Multiwfn函数分析了AMT在前线分子轨道中电子的成分比例和作用,发现对缓蚀剂AMT的理论分析与实验结果相一致。     

柱前衍生-高效液相色谱荧光法测定人血浆中乙酰半胱氨酸及其生物等效性研究

建立一种快速、准确测定人血浆中乙酰半胱氨酸(N-acetylcysteine,NAC)含量的柱前衍生-高效液相色谱荧光法,并使用该方法对NAC不同剂型间的人体生物等效性进行研究。以NAC与N-(1-芘)马来酰亚胺(N-(1-Pyrenyl)maleimide,NPM)进行衍生化反应后进样测定;采用Diamonsil C18色谱柱(5μm×150 mm×4.6 mm)分离,流动相组成为:乙腈-10mmol·L-1NaH2PO(4含TMA 10mmol·L-1,H3PO4调pH至3.4)为50∶50。采用上述方法测定人血浆中NAC浓度,计算药物动力学参数并进行生物等效性评价。NAC 0.1～6.58μg·mL-1的浓度范围内呈良好线性,血浆中NAC定量下线为0.1μg·mL-1,方法回收率在85.3%-103.3%之间,日内、日间RSD均小于15%。该方法准确、快速、灵敏,可用于NAC的治疗药物监测、人体内药代动力学及生物等效性研究,两种制剂生物等效。     

Solvent extraction coupled on-line to a reversed micellar mediated chemiluminescence detection system for trace-level determination of atropine

A fast and sensitive method for the determination of atropine, an alkaloid closely related to cocaine, is proposed. The principles of on-line ion-pair formation of alkaloid-metal complexes and liquid-liquid extraction are applied to the chemiluminescence determination of atropine. On mixing with a reversed micellar medium of cetyltrimethylammonium chloride in dichloromethane-cyclohexane (1:1 v/v)-water (0.3 M Na2CO3) containing luminol, the ion-pair complex of tetrachloroaurate(III) with atropinium produced an analytical chemiluminescence signal when it entered the reversed micellar water pool. Using the reverse-flow injection and chemical conditions optimized for atropine in aqueous samples, a detection limit of 1 ng/mL was achieved and a linear calibration graph was obtained with a wide dynamic range from 10 ng/mL to 100 micrograms/mL. The proposed method is simple and provides a good precision with a relative standard deviation (n = 6) of ca. 3% at the atropine concentration of 100 ng/mL. After a preliminary study involving the potential interference from species of organic, inorganic, and metallic nature, the method was applied to the determination of atropine in artificial urine samples and of atropine and scopolamine in pharmaceutical formulations.     

青霉素发酵液超滤用膜的切割相对分子质量

提出表示发酵液超滤效果的定量评价方法．使用不同切割相对分子质量的超滤膜，在小滤器上处理青霉素发酵液，分别利用吸光度法、蛋白质含量法、溶媒萃取法和高效液相色谱法对比超滤液质量，得到了青霉素发酵液超滤处理用膜的适宜切割相对分子质量和膜型号、     

SrTiO3/TiO2 heterostructure nanowires with enhanced electron--hole separation for efficient photocatalytic activity

Heterostructure is an effective strategy to facilitate the charge carrier separation and promote the photocatalytic performance. In this paper, uniform SrTiO₃ nanocubes were in-situ grown on TiO₂ nanowires to construct heterojunctions. The composites were prepared by a facile alkaline hydrothermal method and an in-situ deposition method. The obtained SrTiO₃/TiO₂ exhibits much better photocatalytic activity than those of pure TiO₂ nanowires and commercial TiO₂ (P25) evaluated by photocatalytic water splitting and decomposition of Rhodamine B (RB). The hydrogen generation rate of SrTiO₃/TiO₂ nanowires could reach 111.26 mmol·g⁻¹·h⁻¹ at room temperature, much better than those of pure TiO₂ nanowires (44.18 mmol·g⁻¹·h⁻¹) and P25 (35.77 mmol·g⁻¹·h⁻¹). The RB decomposition rate of SrTiO₃/TiO₂ is 7.2 times of P25 and 2.4 times of pure TiO₂ nanowires. The photocatalytic activity increases initially and then decreases with the rising content of SrTiO₃, suggesting an optimum SrTiO₃/TiO₂ ratio that can further enhance the catalytic activity. The improved photocatalytic activity of SrTiO₃/TiO₂ is principally attributed to the enhanced charge separation deriving from the SrTiO₃/TiO₂ heterojunction.     

纳滤在L-鸟氨酸后提取中的应用研究

研究了采用纳滤技术代替活性碳对L-鸟氨酸发酵液进行脱色的可行性.从6种有机膜中选择了截留分子量为500的纳滤膜,并考察了料液pH、温度、压力、离子强度对L-鸟氨酸膜透过性能的影响.结果表明膜透过最优条件为:料液温度t=45℃、pH=9.0、操作压力p=2.0 MPa,在此条件下渗滤透过液的透光率T430 nm=96%,L-鸟氨酸收率达到95.8%.此方法在技术上是完全可行的.     

Subzero-temperature liquid-liquid extraction of benzodiazepines for high-performance liquid chromatography.

On the basis of the phenomenon that hydrophilic acetonitrile is separated from the aqueous phase at -20 degrees C, we employed a novel extraction method, "subzero-temperature liquid-liquid extraction", to extract benzodiazepines (estazolam and triazolam) from serum or aqueous solution for liquid chromatography. A 1:1 mixture of acetonitrile and the specimen was cooled at -20 degrees C for 20 min to separate the acetonitrile and aqueous phases. The acetonitrile phase was directly injected into a high-performance liquid chromatograph. Recovery rates of the drugs following the first subzero-temperature liquid-liquid extraction were 50.3 +/- 0.6-54.0 +/- 0.9%, which were lower than those (73.9 +/- 3.3-80.6 +/- 0.6% and 81.6 +/- 4.7-96.1 +/- 2.6%) of the first conventional liquid-liquid extraction using diethyl ether and solid-phase extraction using a Sep-Pak C18 column, respectively. However, three to four repeated subzero-temperature liquid-liquid extractions and conventional liquid-liquid extractions resulted in recovery of almost 100% of the drugs. In the chromatogram of the benzodiazepines recovered from serum by the subzero-temperature extraction, no coextracted component interfered with determination of the drugs. Detection limits of the drugs were 0.02-0.08 microgram/mL, and coefficients of variance were 1.14-2.17% suggesting high reproducibility.     

Synthesis of Ni nanoparticles by reduction of NiCl2 ionic clusters in the confined space of AOT reversed micelles

Stable Nickel nanoparticles have been synthesized by a novel synthetic route based on the reduction of NiCl₂ ionic clusters in the confined space of reversed micelles. The reaction was carried out by adding anhydrous NaBH₄/ethanol solution to a solution of NiCl₂ ionic clusters nanoencapsulated in bis(2-ethylhexyl)sulfosuccinate (AOT) reversed micelles in the presence of n-dodecylmercaptane as capping agent. As highlighted by FT-IR, an extraction with water eliminates surfactant and side products leaving lipophilic Nickel nanoparticles to be dispersed in the organic solvent. UV-Vis investigation ascertained the formation of stable metal Nickel nanoparticles exhibiting novel optical properties.     

Application of single drop microextraction for analysis of chemical warfare agents and related compounds in water by gas chromatography/mass spectrometry

Retrospective detection and identification of chemical warfare agents (CWAs) is important from the verification point of view of the Chemical Weapons Convention. In the present work, a novel method for determination of CWAs and their markers in water has been described. It is based on a single drop micro extraction (SDME) of analytes and gas chromatography/mass spectrometric identification. Extraction conditions, such as solvent selection, agitation, extraction time, and salt content, were found to have significant influence on SDME. The conditions optimized for extraction of CWAs were 1 microL CH2Cl2/CCl4 (3:1 v/v), 30-min extraction time, 300-rpm stirring rate, and with or without NaCl addition. Under optimized conditions, comparison of SDME, solid-phase microextraction, and liquid-liquid extraction was also made. The limit of detection by SDME ranged from 75 to 10 microg L(-1) at a signal-to-noise ratio of 10:1.     

Surfactant assisted synthesis and spectroscopic characterization of selenium nanoparticles in ambient conditions

In this work, an attempt has been made to synthesize well-distributed stable selenium (Se) particles of nanosize dimensions via an aqueous micellar solution by the assistance of surfactants of two different polarities (anionic, sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and cationic, hexadecyltrimethylammonium bromide (CTAB)). The morphology of the particles was examined with transmission electron microscopy (TEM). X-ray analysis reveals that the particles have a monoclinic structure. The band gap of the particles was determined from UV-visible optical spectroscopic results. The size variation was estimated by employing a quantum confinement effect equation. The evolution of the selenium nanoparticles in AOT and CTAB micellar media was corroborated with the time-dependent absorption spectra. The influence of hydrazine hydrate concentrations on the formation kinetics of Se nanoparticles was also investigated. The capping ability of the surfactants has been quantitatively evaluated from Fourier transform infrared (FTIR) studies.     

Enhancement of the Skin Permeation of Clindamycin Phosphate by Aerosol OT/1-Butanol Microemulsions

Microemulsions of water/isopropyl palmitate (IPP)/Aerosol OT (AOT)/1-butanol were developed as alternative formulations for topical delivery of clindamycin phosphate. Effect of AOT:1-butanol ratios on microemulsion region existence in the pseudoternary phase diagrams was investigated. The 2:1 AOT:1-butanol provided the largest microemulsion region. Five microemulsions of 1% w/w clindamycin phosphate were prepared and characterized. The permeation through human epidermis of the microemulsions was evaluated and compared with the 70% isopropanol solution using modified Franz diffusion cells. The drug permeation from all microemulsions was found to be significantly greater than that from the solution, indicating the enhancement of the skin permeation by the microemulsions. Within the same microemulsion type, the drug permeation increased with increasing the amount of AOT:1-butanol. The drug permeation from oil-in-water (o/w) microemulsions was relatively higher than that from water-in-oil (w/o) microemulsions. In addition, all microemulsions were stable for at least three months at 30 ± 1°C.