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1.
刘布鸣  苏小川 《色谱》2006,24(2):211-211
多廿醇是从制糖滤泥中分离得到的一种高级脂肪伯醇天然混合物,其化学组成分析未见报道。本文采用气相色谱法(GC)和气相色谱/质谱法(GC/MS),对其组分和结构进行了分析和鉴定。  相似文献   

2.
化学吸附纤维制备、性能及应用研究进展   总被引:20,自引:0,他引:20  
综述了20年来作者对化学吸附纤维(离子交换、螯合)制备、性能及应用研究结果.包括已发表的文章、未全丈发表的会议报告及尚未发表的研究结果.化学吸附纤维制备研究:基体纤维有聚丙烯、聚丙烯腈、聚氯乙烯、聚乙烯醇纤维,采用方法有辐射引发、化学引发、大分子化学转化,研制了强酸、弱酸性阳离子交换纤维;强碱、弱碱性阴离子交换纤维、螯合纤维.应用研究:对金、铀、重金属等离子的吸附和分离;在填充床电渗析中的应用、吸附气体中H2S、CO2、NH3、HCl、SO2,以及CO2、H2S的分离;废水处理等.  相似文献   

3.
民族药化学指纹图谱研究进展   总被引:1,自引:0,他引:1  
化学指纹图谱是民族药质量评价体系的重要组成部分,其发展与药材质量可控、安全有效关系紧密。目前薄层色谱法、高效液相色谱法、气相色谱法、红外光谱法、紫外光谱法、拉曼光谱法、X射线衍射技术、核磁共振等多种方法已被用于民族药的化学指纹图谱研究。该文对近年国内外相关文献进行总结,探讨化学指纹图谱在民族药真伪鉴别、产地区分、质量评价等方面的应用前景,以期为民族药的资源评价、质量控制和创新发展提供有益参考。  相似文献   

4.
用气相色谱法测定水样中的有机组分,通过组分单位浓度对化学耗氧量的贡献因子得到样品中化学耗氧量的总量。该方法与经典的重铬酸钾法相比,不受测定条件影响,测定步骤简便,测定范围宽,结果与重铬酸钾法等效。  相似文献   

5.
氟碳铈矿精矿的分步氯化—化学气相传输反应   总被引:4,自引:0,他引:4  
以气态配合物LnAlnCl3n 3(Ln=镧系元素)为载体,研究了从氟碳铈矿精矿中提取分离稀土元素的分步氯化-化学气相传输反应,精矿加热至800K,然后在800-1300K氯化,生成氯化物在1300K与配件反应生成气态配合物,并化学传输分离6h,CaCl2和BaCl2留在残渣中,研究结果表明,递减温度场和波浪形温度场中的化学传输反应呈现明显不同的特性。  相似文献   

6.
高效液相色谱中的化学衍生法   总被引:5,自引:0,他引:5  
邱宗荫  李惠芝  曾少波 《色谱》1989,7(6):340-349
色谱技术中的化学衍生法系指在色谱过程中用特殊的化学试剂(一般称为衍生化试剂或标记试剂)使样品成分转变相应的衍生物之后进行分离检测或进行检测的方法。近十年来,化学衍生法在高效液相色谱法中的应用受到重视,发展较快。在高效液相色谱法中,化学衍生化的目的为:1.将紫外一可见强吸收功能基团引入被检测对象或将其转变为荧光衍生物,以提高检测灵敏度;2.提高对分析样品的分离和选择性。  相似文献   

7.
液相组合化学   总被引:5,自引:0,他引:5  
许家喜  麻远 《化学通报》2002,65(3):145-152
综述了液相组合化学的研究进展,重点介绍了液相组合合成中的分离纯化方法和合成方法策略,基本分离纯化方法包括利用固相载体协助分离纯化法,相萃取分离纯化法和色谱法,主要合成方法策略有平行合成策略和索引合成策略。  相似文献   

8.
环境样品中硝基苯类化合物的分析方法研究进展   总被引:4,自引:0,他引:4  
主要介绍了我国近年来在环境样品中硝基苯类化合物的分析研究进展,内容包括:光度法(还原-偶氮光度法、阻抑动力学光度法、化学计量学分光光度法、人工神经网络-分光光度法)、气相色谱法(固相微萃取-毛细管气相色谱法、树脂吸附-气相色谱法、液-液微萃取气相色谱法、超声萃取-气相色谱法)、高效液相色谱法(反相高效液相色谱法、固相萃取-高效液相色谱法)和极谱法等分析方法。  相似文献   

9.
用傅氏变换红外光谱(FTIR)研究了不同方法制备的Bi系超导体原始粉末研磨过程中;自环境气相中的化学吸附行为.结果表明;在空气中研磨,粉末化学吸附空气中的CO2和H2O在氩气中研磨则无化学吸附现象.用Bi系超导体晶体结构的特征分析了吸附机理.  相似文献   

10.
本工作研究了吸附剂、催化剂等固体添加物混入微孔聚砜膜中对C_1化学用原料气-H_2和CO的选择透气性的影响,普遍的结果是显著地提高了膜对气体的分离因子,且与吸附剂、催化剂的化学、物理性质有一定关系。因此,气体的渗透过程除了有诺森流和粘性流外,还可能生成吸附态过渡络合物,影响气体的吸附-脱附能力而提高了分离因子,提出了过渡吸附态的气体促进输送机理。  相似文献   

11.
The application of high-field Fourier transform nuclear magnetic resonance (NMR) spectroscopy to the analysis of biological fluids such as urine, plasma and bile is described. Applications include areas such as clinical chemistry, experimental and clinical toxicology and drug metabolism studies. In the case of proton NMR some means of attenuating or eliminating the interference due to water protons is required and suitable strategies for achieving this are discussed. The use of 2-dimensional NMR or solid-phase extraction/chromatography to enable the identification of unknowns is discussed and the potential usefulness of 19F NMR for studying the metabolism of fluorinated xenobiotics is highlighted.  相似文献   

12.
Protein-based liquid chromatography stationary phases are used in bioaffinity chromatography for studying drug-protein interactions, the determination of binding affinities, competitive and allosteric interactions, as well as for studying protein-protein interactions. This review addresses the development and characterization of protein-based stationary phase, and the application of these phases using frontal and zonal chromatography techniques. The approach will be illustrated using immobilized heat shock protein 90α and the immobilized estrogen related receptor stationary phases. In addition, the review discusses the use of the protein-coated magnetic beads for ligand and protein fishing as well as for the identification of unknown ligands from cellular or botanical extracts.  相似文献   

13.
The methylation of a 23-kDa nuclear protein increased after partial hepatectomy and methylation returned to basal levels after the initial stage of regeneration. The methylating enzyme was partially purified from rat liver by ammonium sulfate precipitation, DEAE-anion exchange chromatography and Butyl-Sepharose chromatography. The 23-kDa protein was purified from a nuclear fraction of liver tissue with SP-Sepharose. When the 23-kDa protein was methylated with the partially purified methyltransferase and analyzed on C(18) high performance liquid chromatography (HPLC), the methylated acceptor amino acid was monomethyl lysine (MML). Previously, only arginine N-methylation of specific substrate proteins has been reported during liver regeneration. However, in this report, we found that lysine N-methylation increased during early hepatic regeneration, suggesting that lysine N-methylation of the 23-kDa nuclear protein may play a functional role in hepatic regeneration. The methyltransferase did not methylate other proteins such as histones, hnRNPA1, or cytochrome C, suggesting the enzyme is a 23-kDa nuclear protein- specific lysine N-methyltransferase.  相似文献   

14.
In studying the reactions of thermal degradation of solid samples more information can be obtained by correlation gas chromatography than by conventional pyrolysis gas chromatography. This is due to a multiplex character of the method leading to a rapid decrease in detection limit.  相似文献   

15.
For the purpose of studying the mechanism of thermal degradation of poly[(tetramethyl-p-silphenylene) Siloxane] (poly TMPS) a series of polymers with silphenylene and siloxane bonds in the main chain were prepared and subjected to thermogravimetry (TG) and pyrolysis study. Analyses of products from poly TMPS degradation (in vacuum at a constant temperature) by gas chromatography (GC), infrared (IR), nuclear magnetic resonance (NMR) spectroscopy, and gas chromatography-mass spectrometry (GC–MS) revealed that degradation occurs at the silphenylene bonds. The TG curves obtained in He for heating rates of 1,2,2.5,7.5, and 10°C/min were analyzed by the Ozawa method; activation energies of 39 ± 1 and 45 ± 2 kcal/mol were obtained respectively for the initial cleavage of the methyl side group and the later-stage scission of the main-chain silphenylene bond which leads to a major weight loss. The results agree with those obtained for other structurally similar polymers.  相似文献   

16.
A large part of Mexican artistic heritage was created with artists’ acrylic emulsion paints, so it is crucial to investigate their composition, behavior, and decay. Acrylic films are complex chemical systems combining organic and inorganic compounds; therefore, the degradation studies require a variety of techniques. We characterize three acrylic films before and after ultraviolet aging. The relative composition of the polymer matrix was studied by nuclear magnetic resonance, pyrolysis—gas chromatography—mass spectrometry and direct analysis in real time mass spectrometry with direct analysis in real time. The inorganic compounds and surfaces were characterized by microscopic techniques, such as digital microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and micro X-ray diffraction. The combined use of these techniques proved to be effective for an in-depth study of the acrylic painting degradation process. The main results were the gradual degradation for the organic surfactant and the loss of inorganic aggregates (talc and carbonates), that led to the disruption of the paint film, which points out the importance of studying the role and interaction of all compounds.  相似文献   

17.
烷基多苷的分析测定   总被引:4,自引:0,他引:4  
GC、^1H-NMR和^13C-NMR核磁共振技术都能准确地测量出烷基多苷的平均聚合度,可判断出烷基多苷中主要苷类的出峰位置。  相似文献   

18.
Oxygenated neutral constituents of a tumor-inhibiting fraction of cigarette smoke condensate were separated from interfering phenolic compounds by a combination of silicic acid and gel chromatography. Silicic acid adsorption and Bio-Beads gel chromatography separated aliphatic from aromatic ketones, and gel chromatography on Sephadex LH-20 resolved aromatic ketones from phenols. Identifications were achieved by studying individual fractions by g.c. and g.c.—m.s.  相似文献   

19.
Summary: In this work an investigation of the chain end groups produced in the free radical copolymerization of vinilydene fluoride (VDF) and hexafluoropropylene (HFP) is performed. Type and amount of chain end groups are evaluated by a meticulous analytical characterization of VDF/HFP copolymer. At first pulsed gradient spin-echo nuclear magnetic resonance (spin-echo NMR) is used to identify all the chain end groups also at very low concentration (equal to 0.1 mmol · Kg−1). The instrument sensitivity is increased of an order of magnitude in comparison with the traditional NMR. Moreover potentiometric titration and ion chromatography (IC) are also used to study the chain end groups and, as a consequence, the nature and the amount of the acidity showed by the polymer chains. In details two intensity of acidity are detected by potentiometric titration, namely strong and weak. The strong acidity is associated to the presence of residual surfactant and can be removed washing the polymer, while the weak acidity is due to free molecules of fluoride acid (HF). The standard ion chromatography facility is properly modified to quantify the fluoride in the polymer matrix without any pre extraction in water. Thanks to this the HF concentration in the polymer is evaluated with high accuracy. A detailed kinetic scheme for the VDF/HFP polymerization is also proposed taking into account all the findings obtained studying the chain end groups.  相似文献   

20.
Two complementary chromatographic methods, viz., ion-exclusion chromatography and gas-liquid chromatography, are suggested for studying the chemical composition and the standardization of medicinal-plant raw materials and plant mixtures. An algorithm for selecting one of two methods, which takes into account the component composition in plant mixtures, as well as the classification of marker sub-stances according to the degree of their occurrence in specific types of medicinal-plant raw materials, are proposed.  相似文献   

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