毛细管胶束电泳测定番茄中环境激素2,4-滴的含量

用毛细管胶束电泳法测定了番茄中环境激素2,4-滴的含量。研究了电泳缓冲液的种类、体积分数、pH值和有机调节剂乙醇的变化对分离效果的影响。在分析电压为25kV、pH值7.0、20mmol/L磷酸氢二钠缓冲液 30%乙醇为缓冲溶液、检测波长225nm条件下,在线性质量浓度范围为6.0×10-1～9.375×10-4g/L时,回归方程为y=0.00135x-0.00214,相关系数r=0.99967,检测限为0.9375mg/L;测得样品中2,4-滴的含量为0.07598mg/kg,回收率范围为98.2%～104.6%,其RSD为2.1%～4.5%。该方法具有操作简单、快速方便及自动化程度高、重现性好等优点。     

Determination of aniline and its derivatives in environmental water by capillary electrophoresis with on-line concentration

This paper describes a simple, sensitive and environmentally benign method for the direct determination of aniline and its derivatives in environmental water samples by capillary zone electrophoresis (CZE) with field-enhanced sample injection. The parameters that influenced the enhancement and separation efficiencies were investigated. Surprisingly, under the optimized conditions, two linear ranges for the calibration plot, 1-50 ng/mL and 50-1000 ng/mL (R > 0.998), were obtained. The detection limit was in the range of 0.29-0.43 ng/mL. To eliminate the effect of the real sample matrix on the stacking efficiency, the standard addition method was applied to the analysis of water samples from local rivers.     

环糊精及其衍生物在高效毛细管电泳手性拆分中的应用

高效毛细管电泳 ( HPCE)在手性拆分中的应用近年受到普遍关注。含有手性添加剂环糊精 ( CD)及其衍生物的毛细管区带电泳 ( CZE)和胶束电动毛细管色谱 ( MECC)拆分体系方面研究非常活跃。综述了 CD- CZE和 CD-MECC体系 ,探讨了各体系的拆分机理和各实验条件对拆分结果的影响。     

阿魏酸异辛酯的一锅法合成

用香兰素、丙二酸二乙酯、异辛醇、冰醋酸为主要原料,以甘氨酸为催化剂,经Knoenenagel缩合反应,一锅法合成了阿魏酸异辛酯。研究了原料摩尔比、甘氨酸用量、反应时间等对阿魏酸异辛酯收率的影响。结果表明,最佳反应条件:香兰素6.08g(0.04mol),n(丙二酸二乙酯)/n(香兰素)=1.4,n(甘氨酸)/n(香兰素)=0.15,n(异辛醇)/n(丙二酸二乙酯)=12,反应时间8h,在该条件下目标产物阿魏酸异辛酯产率达75.2%。用核磁共振波谱及红外光谱对所得目标产物进行了表征。     

喷射环流反应器中甲苯气相三氧化硫磺化

<正>对甲苯磺酸是制备对甲酚的重要中间体。目前,工业上主要采用甲苯浓硫酸磺化的方法生产,该方法硫酸利用率低,生产过程产生大量废酸,造成环境污染严重;同时,由于磺化产物中,间甲苯磺酸含量高达4%以上,以此为原料生产高纯对甲酚的收率低、成本高、工艺复杂,以SO_3为磺化剂能克服以上不足。对于大相对分子质量的烷基苯（如十二烷基苯）的SO_3磺化早已工业化,关于小相对分子质量烷基苯（如甲苯）的磺化,1983年,Sohrabi建立了气液传质模型,Davidsohn提出了多釜串联生产对甲苯磺酸的专利技术,但至今未见有工业化报道,针对SO_3磺化甲苯具有反应速度快,放热量大等特点,本文首次将用于生化反应过程的喷射环流反应器用于气相SO_3磺化甲苯的反应过程,克服了釜式磺化反应器传质比表面积小、体积大及降膜磺化反应器内易出现局部过热、结构复杂等不足。通过实验,对反应产物的物性变化情况、反应器内的气含率特性及工艺条件进行了初步研究,为工程放大提供了合理的依据。     

Myochrysine solution structure and reactivity

We have determined the framework structure of Myochrysine (disodium gold(I)thiomalate) in the solid state and extremely concentrated aqueous solution, previously. It consists of an open chain polymer with linear gold coordination to two thiolates from the thiomalic acid moieties which bridge between pairs of gold atoms providing an Au-S-Au angle of 95 degrees . The question remained: was this structure relevant to the dilute solutions of drugs administered and the still lower concentrations of gold found in the bodies of patients (typically 1 ppm Au in blood and urine or 5 muM in Au). We have provided an answer to that question using extended X-ray absorption spectroscopy (EXAFS) and capillary zone electrophoresis (CZE). EXAFS studies confirm that the polymeric structure with two sulfur atoms per gold atom persists from molar concentrations down to millimolar concentrations. CZE is able to separate and detect Myochrysine at millimolar levels. More importantly, at micromolar levels Myochrysine solutions exhibit identical CZE behavior to that measured at millimolar levels. Thus, aqueous solutions of the drug remain oligomeric at concentrations commensurate with those found in patient blood and urine.The reactivity of Myochrysine with cyanide, a species especially prevalent in smoking patients, was explored using CZE. Cyanide freely replaces thiomalic acid to form [Au(CN)(2)](-) and thiomalic acid via a mixed ligand intermediate. The overall apparent equilibrium constant (K(app)) for the reaction is 6x10(-4)M(-1). Further reaction of [Au(CN)(2)](-) with a large excess of L, where L is cysteine, N-acetylcysteine, or glutathione, shows that these amino acids readily replace cyanide to form [AuL(2)](-). These species are thus potential metabolites and could possibly be active forms of gold in vivo. That all of these species are readily separated and quantified using CZE demonstrates that capillary electrophoresis is an accessible and powerful tool to add to those used for the study of gold-based antiarthritis drugs.     

Long-chain phenols: XX. Synthesis of oxidative degradation products from the methylated component phenols ofAnacardium occidentale and other phenolic lipids: Confirmation of the structure of the parent phenols and of a related material

A general procedure for the determination of the first double bond position in the side-chain of a phenolic lipid has been investigated and, in the first place, the phenols of natural cashew nut-shell liquid (Anacardium occidentale) have been examined. An improved oxidative degradation procedure has been applied consisting of methylation by the phase transfer procedure, hydroxylation with performic acid and oxidation of the mixture of vicinal diols with periodic acid (Malaprade reaction) followed by reduction of the aldehyde fragments with sodium borohydride. The aromatic moieties from the 15∶1, 15∶2 and 15∶3 constituents of cardanol methyl ether, cardol dimethyl ether and dimethyl anacardate were shown to be 8-(3-methoxyphenyl)octan-1-ol, 8-(3,5-dimethoxyphenyl)octan-1-ol and 6-(8-hydroxyocyl)salicylate methyl ether, respectively. The first two octanols were identical to synthetic materials, thus confirming the 8-position for the first double bond in the side-chain of cardanol methyl ether and cardol dimethyl ether constituents. Methyl 6-(8-hydroxyoctyl)salicylate relationship in a series of synthetic reference materials of log (retention time) to the methylene chain length. The synthetic acids 8-(3-methoxyphenyl)octanoic acid, 8-(3,5-dimethoxyphenyl)octanoic acid and 6-(7-carboxyheptyl)salicylic acid methyl ether have been obtained pure for the first time and correspond to the oxidation products of the aromatic aldehyde fragments from the Malaprade reaction stage. The unsaturation in peladjauol, 17∶1-bishomocardanol methyl ether, fromPentaspadon officinalis was confirmed to be at the 8-position by the identity of the anilides of synthetic 8-(3-methoxyphenyl) octanoic acid and of the oxidative degradation product. For part XIX, see ref. 1.     

离子液体中6-羟基-2(1H)-喹啉酮的合成

研究了对甲氧基苯胺经溴化、酰化和Heck反应在离子液体中合成6-羟基-2(1H)-喹啉酮的方法。对甲氧基苯胺与离子液体[bmim]Br3发生选择性溴化反应,以98.2%的收率得到质量分数为99.5%的2-溴-4-甲氧基苯胺;2-溴-4-甲氧基苯胺与丙烯酰氯发生酰化反应,以95.7%的收率得到N-(2-溴-4-甲氧基苯基)丙烯酰胺;在离子液体、醋酸钯、碳酸钾和1,3-双(二苯基膦)丙烷反应体系中,N-(2-溴-4-甲氧基苯基)丙烯酰胺顺利地发生分子内Heck反应,以91.5%的收率得到6-羟基-2(1H)-喹啉酮。该方法原料易得,反应条件易控制,收率高,离子液体可以重复使用,对环境友好。     

离子液体中6-羟基-2(1H)-喹啉酮的合成研究

研究了对甲氧基苯胺经溴化、酰化和Heck反应在离子液体中合成6-羟基-2(1H)-喹啉酮的方法。对甲氧基苯胺与离子液体[bmim]Br3发生选择性溴化反应,以98.2%的收率得到质量分数为99.5%的2-溴-4-甲氧基苯胺;2-溴-4-甲氧基苯胺与丙烯酰氯发生酰化反应,以95.7%的收率得到N-(2-溴-4-甲氧基苯基)丙烯酰胺;在离子液体、醋酸钯、碳酸钾和1,3-双(二苯基膦)丙烷反应体系中,N-(2-溴-4-甲氧基苯基)丙烯酰胺顺利地发生分子内Heck反应,以91.5%的收率得到6-羟基-2(1H)-喹啉酮。该方法原料易得,反应条件易于控制,反应收率高,离子液体可以重复使用,对环境友好。     

Determination of Branched-Chain Amino Acids in Food Supplements and Human Plasma by a CE-MS/MS Method with Enhanced Resolution

In the presented study, a capillary electrophoresis-mass spectrometry method combining high separation efficiency and sensitive detection has been developed and validated, for the first time, to quantify branched chain amino acids (valine, isoleucine, leucine) in commercial food and sport supplement samples and human plasma samples. The separations were performed in a bare fused silica capillary. The background electrolyte was composed of 500 mM formic acid with pH 2.0. The plasma sample pretreatment was realized by simple protein precipitation with acetonitrile. Injection of a short zone of highly basic electrolyte before the sample injection and application of the negative pressure on the separation were accompanied by enhanced resolution of the isobaric amino acids—isoleucine and leucine. The developed method was characterized by favorable validation parameters, such as linearity (r² > 0.99), accuracy and precision, the limit of detection, lower limit of quantification, or robustness. These parameters were more than sufficient for the quantification of branched chain amino acids in various samples. The determined concentrations of branched chain amino acids in food and sports supplements were in very good agreement with the content declared by the manufacturer. The investigated concentrations of branched chain amino acids were in the range 294.68–359.24 µM for valine, 91.76–95.67 µM for isoleucine, and 196.78–251.24 µM for leucine. These concentrations fall within the physiological limits. The developed CE-MS/MS method represents a suitable alternative to traditional approaches used in branched chain amino acid quality control and bioanalysis.     

Kinetics and mechanism of sulphite oxidation on a rotating platinum disc electrode in an alkaline solution

The reaction of sulphite at high pH and room temperature has been examined by cyclic voltammetric methods on a rotating platinum disc electrode. The mechanism of the oxidation reaction is studied by varying the sweep rate, the rotation rate and the concentration. The oxidation of sulphite on a platinum electrode under alkaline conditions appears to follow a catalytic reaction mechanism where weakly adsorbed sulphite is first oxidised to a strongly adsorbed sulphite radical in the rate-determining step. In the next step two sulphite radicals combine and form dithionate, which disproportionate into sulphite and sulphate.     

氨基酸的高效毛细管区带电泳电导检测的研究

用阴离子交换膜制作的导电接口连接毛细管和自制的微电导池检测器 ,在自行组装的电泳装置上研究了几种氨基酸混合液的电泳分离和柱后电导检测 ,探讨了缓冲体系及其浓度、pH值、电泳电压等对氨基酸分离的影响 ,结果令人满意。     

钴镍协同萃取体系

评述了自１９６６年以来报道的有关钴镍协同萃取的文献．主要介绍了磷酸、羧酸以及磺酸类萃取剂与含氮螯合萃取剂或非螯合萃取剂组成的协同萃取体系．此外，对一些由胺类萃取剂加磺酸或羧酸类萃取剂加吡啶羧酸酯组成的协同萃取也作了简单介绍．讨论了这些协同萃取体系萃取钴镍的反应机理、特点及其潜在的应用价值．     

毛细管区带电泳在生物农药残留分析中的应用

毛细管电泳(CE)具有所需样品量小、分离效率高等特点,已经引起越来越多的关注,并将它应用到农药残留的检测中。对目前的多种检测方法的优缺点及其在农药残留检测中的应用情况进行了综述,同时介绍了生物农药的毛细管区带电泳(CZE)的检测情况,展望了CZE在农药残留分析与检测中的应用前景。     

3-(2,8,9-三氧杂-5-氮杂-1-锗三环[3.3.3.0]十一烷基)-3-(4-羟基-3-甲氧基苯基)丙酸的合成

以氧化锗、次亚磷酸钠、浓盐酸为原料经氧化还原反应合成三氯锗仿,三氯锗仿再与阿魏酸经麦克尔加成反应得到3-三氯锗基-3-(4-羟基-3-甲氧基苯基)丙酸,然后与甲醇钠反应生成3-三甲氧锗基-3-(4-羟基-3-甲氧基苯基)丙酸,再与三乙醇胺发生烷基转移反应生成标题化合物.     

Chlorinated long-chain fatty acids. Their properties and reactions. XII. The dechlorination pathways of sodium 9(10)-chloro-10(9)-oxooctadecanoates in aqueous sodium hydroxide solution

The dechlorination pathways of the equal mixture of 9-chloro-10-oxo-and 10-chloro-9-oxooctadecanoic acids in aqueous sodium hydroxide solution were investigated. The reaction product mixture of these acids, isolated after dechlorination, was found to contain α-hydroxyoxo and long-chain alkanedioic acids at a weight ratio of 15 to 1. The most abundant compounds formed were 9-hydroxy-10-oxo and 10-hydroxy-9-oxooctadecanoic acids. The minor reaction products consisted of Favorskii rearrangement products, 2-heptyl-1,11-undecanedioic, 2-octyl-1,10-decanedioic and 2-nonyl-1,9-nonanedioic acids. On the other hand, the expected α,β-unsaturated oxoacids could not be detected in the reaction product mixture.     

Contribution of Capillary Zone Electrophoresis Hyphenated with Drift Tube Ion Mobility Mass Spectrometry as a Complementary Tool to Microfluidic Reversed Phase Liquid Chromatography for Antigen Discovery

The discovery of new antigens specific to multiple myeloma that could be targeted by novel immunotherapeutic approaches is currently of great interest. To this end, it is important to increase the number of proteins identified in the sample by combining different separation strategies. A capillary zone electrophoresis (CZE) method, coupled with drift tube ion mobility (DTIMS) and quadrupole time-of-flight mass spectrometry (QTOF), was developed for antigen discovery using the human myeloma cell line LP-1. This method was first optimized to obtain a maximum number of identifications. Then, its performance in terms of uniqueness of identifications was compared to data acquired by a microfluidic reverse phase liquid chromatography (RPLC) method. The orthogonality of these two approaches and the physicochemical properties of the entities identified by CZE and RPLC were evaluated. In addition, the contribution of DTIMS to CZE was investigated in terms of orthogonality as well as the ability to provide unique information. In conclusion, we believe that the combination of CZE-DTIMS-QTOF and microfluidic RPLC provides unique information in the context of antigen discovery.     

毛细管电泳-安培检测法测定中药四季青中的6种活性成分

采用毛细管电泳-安培检测法（CE—AD）,同时测定了中药四季青的主要活性成分异香草酸、龙胆酸、山奈酚、槲皮素、咖啡酸和原儿茶酸。考察了工作电极电位、pH值、运行缓冲液的浓度、分离电压和进样时间的影响。在最佳的试验条件下,50mmol／L硼砂缓冲溶液（pH=9．0）为运行缓冲溶液。工作电极为直径300m的碳圆盘电极,检测电位为＋0．95V（vs．SCE）。被测物的线性范围超过3个数量级。该方法成功的被应用于实际样品的分析,获得了令人满意的结果。     

Absorption of oxygen by aqueous sodium sulphite solutions

New data have been reported on the absorption of oxygen by aqueous sodium sulphite solutions with cobalt sulphate as catalyst at 30°C. It is observed that the absorption rate increases up to a critical sulphite concentration beyond which the absorption rate becomes constant and this critical concentration varies with the catalyst concentration. The order of reaction with respect to sulphite and oxygen in the constant absorption rate regime was found to be zero and two respectively. The absorption rate is affected by the total ionic strength (sulphite and sulphate) in addition to the effect of pH and catalyst concentraion. The reported data were also analysed to ascertain the effect of temperature and a relationship has been proposed for prediction of the second order reaction rate constant.     

Conformation analysis of aspartame-based sweeteners by NMR spectroscopy, molecular dynamics simulations, and X-ray diffraction studies

We report here the synthesis and the conformation analysis by 1H NMR spectroscopy and computer simulations of six potent sweet molecules, N-[3-(3-hydroxy-4-methoxyphenyl)-3-methylbutyl]-alpha-L-aspartyl-S-tert-butyl-L-cysteine 1-methylester (1; 70 000 times more potent than sucrose), N-[3-(3-hydroxy-4-methoxyphenyl)-3-methylbutyl]-alpha-L-aspartyl-beta-cyclohexyl-L-alanine 1-methylester (2; 50 000 times more potent than sucrose), N-[3-(3-hydroxy-4-methoxyphenyl)-3-methylbutyl]-alpha-L-aspartyl-4-cyan-L-phenylalanine 1-methylester (3; 2 000 times more potent than sucrose), N-[3,3-dimethylbutyl]-alpha-L-aspartyl-(1R,2S,4S)-1-methyl-2-hydroxy-4-phenylhexylamide (4; 5500 times more potent than sucrose), N-[3-(3-hydroxy-4-methoxyphenyl)propyl]-alpha-L-aspartyl-(1R,2S,4S)-1-methyl-2-hydroxy-4-phenylhexylamide (5; 15 000 times more potent than sucrose), and N-[3-(3-hydroxy-4-methoxyphenyl)-3-methylbutyl]-alpha-L-aspartyl-(1R,2S,4S)-1-methyl-2-hydroxy-4-phenylhexylamide (6; 15 000 times more potent than sucrose). The "L-shaped" structure, which we believe to be responsible for sweet taste, is accessible to all six molecules in solution. This structure is characterized by a zwitterionic ring formed by the AH- and B-containing moieties located along the +y axis and by the hydrophobic group X pointing into the +x axis. Extended conformations with the AH- and B-containing moieties along the +y axis and the hydrophobic group X pointing into the -y axis were observed for all six sweeteners. For compound 5, the crystal-state conformation was also determined by an X-ray diffraction study. The result indicates that compound 5 adopts an L-shaped structure even in the crystalline state. The extraordinary potency of the N-arylalkylated or N-alkylated compounds 1-6, as compared with that of the unsubstituted aspartame-based sweet taste ligands, can be explained by the effect of a second hydrophobic binding domain in addition to interactions arising from the L-shaped structure. In our examination of the unexplored D zone of the Tinti-Nofre model, we discovered a sweet-potency-enhancing effect of arylalkyl substitution on dipeptide ligands, which reveals the importance of hydrophobic (aromatic)-hydrophobic (aromatic) interactions in maintaining high potency.