柱切换高效液相色谱法在生物样品中的应用

评述了柱切换高效液相色谱法（ＣＳＨＰＬＣ）在生物样品分析中的应用进展．分别对柱切换装置，血样、尿样提取液中被测组分浓度的测定，在线浓缩样品技术以及ＣＳＨＰＬＣ的联用进行了介绍．     

二维液相色谱阀切换接口技术的发展及应用

在复杂样本分析中,一种分离模式往往不能提供足够的分离度,组合不同的分离模式构建二维液相色谱系统是解决这一问题的有效途径。阀切换接口是二维液相色谱柱切换技术的核心,接口技术影响系统的分离度和灵敏度。传统的接口技术在生物、药学、食品、环境等领域得到了广泛应用,近20年发展了众多新型的接口技术来解决二维液相色谱中正交组合溶剂不兼容问题。本文综述了柱切换接口技术的原理和应用,并总结了近5年利用柱切换二维液相分析技术的进展,期望为二维液相色谱技术的发展和应用提供借鉴。     

高效液相色谱整体柱在药物分离分析中的应用进展

本文对高效液相整体柱在药物分离分析方面的应用进行了综述.主要介绍了以烷氧基硅烷为主要原料,采用溶胶-凝胶法制备的硅胶整体柱,由于其具有微米级通孔结构和大的比表面积,他们在高效、快速分离小分子物质方面得到广泛地应用.对于聚合物整体柱,主要介绍了包括分子印迹聚合物在内的有机聚合物整体柱在药物分离、生物样品的处理等方面的应用.     

电荷转移络合物理论在生物医学方面的应用

综述了有机电荷转移络合物理论在药物与药物受体作用机理，生物体内的氧化过程，药剂学和药物分析几个方面的应用。     

分析化学

毛细管电色谱（CEC）集毛细管电泳的高柱效和高效液相色谱的高选择性为一体，在药物和生物分析领域有着巨大的：应用潜力。最近，天津大学药物科学与技术学院的万谦宏研究组在Anal．Chem，2007，79（13）：5082～5086发表的论文中，报道了制备毛细管电色谱柱的新方法。利用磁场力将键合十八烷基的磁性微球（Magnetic Microspheres，MM）固定于毛细管中，得到新颖的无塞CEC柱，应用于中性混合物的分离分析，结果可以和其它CEC填充柱相媲美。     

应用前沿亲和色谱研究分子之间相互作用及其应用

分子间的相互作用是一切生物或化学变化的基础。前沿亲和色谱作为通用性的研究分子间相互作用力的工具,利用它可得到分子之间相应的解吸常数K_d,并可对各种配体的亲和力大小进行排序。本文介绍了前沿亲和色谱的工作原理、前沿亲和色谱柱的构建,以及在药物筛选,生物相关领域的应用。与其他研究分子间相互作用的技术作了相应的比较。     

功能化金属-有机框架材料在肿瘤治疗中的研究进展

恶性肿瘤由于其易转移、复发等特点，已经严重危害到人类的生命健康.近年来，研究人员设计了大量纳米药物载体，将抗肿瘤药物安全有效地运载到肿瘤，有效地提高了药效并降低了毒副作用.金属有机框架材料（metal-organic frameworks，MOFs）是一类有序、多孔的晶态材料，具有比表面积大、结构可设计性强、易生物降解等独特优势，已经被广泛应用于气体吸附与分离、催化、药物传递、生物大分子固载以及肿瘤治疗等方面.目前，基于MOFs的生物医用研究主要集中在MOF材料的可控合成，表面修饰，基于MOF独特理化性质发展的多模式成像技术以及肿瘤靶向的药物运载技术等几个方面.主要介绍了基于MOFs构建的生物功能化材料在肿瘤治疗中的应用，并对其在生物医学领域的应用进行了展望.     

多柱色谱技术进展

在色谱分析过程中，利用串联、并联或串并联结合的方式将多根色谱柱组合起来，可以实现高通量和高分辨的分离效果。相比于传统单柱色谱技术，多柱技术很好地满足了批量样品分析和复杂生物样品分离分析的需求，因此引起了广泛关注。该文对多柱技术在多维分离、芯片色谱、毛细管电泳、固定相筛选以及串联色谱等领域的应用进行了综述，并对其发展前景进行了展望。     

气相色谱-质谱联用法在生物样品分析中的应用

概述了气相色谱-质谱技术在生物样品分析及药物测定中的应用.     

酶在光学活性药物合成中的应用

作为天然的生物催化剂，酶催化化学反应具有催化效率和立体选择性高、反应条件温和的特点。酶不仅适于外消旋药物及其合成子的有效拆分，而且可用于光学活性药物手性中心的直接构建。本文介绍水解酶、氧化还原酶及其酶源在光学活性药物合成中的应用。参考文献２９篇     

Increased Flexibility in Multicolumn Chromatography (MC[sbnd]HPLC) via On-line Effluent Mixing Technique

Abstract

In continuation of our work dealing with multicolumn HPLC (MC[sbnd]HPLC) we describe in this paper an on-line on-column fraction trapping technique based on effluent mixing.

To a normal two-column switching set-up (in this case with two RP columns) an additional high-pressure pump gets inserted into the connection line between column A and column B via a low dead volume mixing tee. The in-line respectively off-line switching of pump B and the mobile phase B is time controlled by using a high pressure switching valve. With this set-up it is possible to mix on-line an effluent fraction from column A and transferred onto column B with a highly polar and pH-controlled (e.g. aqueous buffer) new effluent, to reduce or adjust significantly the overall elution strength of this mixed transferred solvent. Thus, several chromatographically effective possibilities can be created in a simple manner, which are for example: (a) pronounced peak compression respectively on-column concentration on column B; (b) due to low elution strength and/or pH adjustment during the trapping period on column B, increments to the overall selectivity of the column switching set-up can be added creating multidimensionality via mobile phase switching; (c) combining the heart cut with the effluent mixing technique enables analysis of trace peaks eluted on the back flank of an overloaded main peak.     

Mixed mode chromatography via column switching for the simultaneous HPLC analysis of lonic and non-lonic nucleic acid constituents

Summary A method is presented for the separation of purine and pyrimidine nucleotides, nucleosides and bases in one analysis. This method uses both the ion-exchange and the reversed-phase modes for the analysis of these compounds. The modes are coupled through automatic switching valves. The use of these valves permits the isolation of either column during the analysis. The nucleotides are separated on an anion-exchange column and the nucleosides and bases on a C-18 column. Total analysis time is approximately one hour, and a very small volume of a sample can be analyzed. The technique is flexible and mobile phase conditions for one column can be altered without affecting the resolution on the other column. The method is applicable to biological matrices.     

Analysis of volatile organic compounds in polymers by dynamic headspace and gas chromatography/mass spectrometry

An experimental method for the analysis of volatile organic compounds in polymers is described. The technique involves dynamic headspace sampling, collection, and concentration of the volatiles in a cold trap, followed by capillary column gas chromatography/mass spectometry. Flow switching is carried out by the Deans switching technique. Four technical polymers used as pharmaceutical packaging materials have been analyzed in order to demonstrate the method.     

Simultaneous determination of peroxydisulfate and conventional inorganic anions by ion chromatography with the column‐switching technique

The application of ion chromatography with the column‐switching technique for the simultaneous analysis of peroxydisulfate and conventional inorganic anions in a single run is described. With this method, conventional inorganic anions were separated by consecutive elution through both the guard column and separation column, but peroxydisulfate that only passed through the guard column had a good peak shape and short retention time. A series of standard solutions consisting of target anions of various concentrations from 0.01 to 75 mg/L were analyzed, with a correlation coefficient (r) ≥ 0.9990. The limits of detection were in the range of 0.49–9.84 μg/L based on the S/N of 3 and a 25 μL injection volume. RSDs for retention time, peak area, and peak height were all <1.77%. A spiking study was performed with satisfactory recoveries between 97.6 and 103.4% for all anions. The quantitative determination of peroxydisulfate and conventional inorganic anions in surface waters was accomplished within 18 min by this column‐switching technique.     

气相毛细管柱切割-反吹技术及归一化法分析汽油中的芳烃(英文)

 发展了一种采用毛细管气相柱切割 反吹技术分析汽油中芳烃的方法。利用强极性毛细管预柱将芳烃保留至n C10 的脂肪族化合物之后 ,并将其反吹到非极性毛细管柱中按沸点详细分离分析。该方法使预柱先流出的组分和分析柱流出的组分通过一个微型三通进入同一检测器中 ,因此可用归一化方法定量分析汽油中的芳烃。该方法可在 15min内完成汽油中苯至C10 芳烃的分析 ,结果的相对标准偏差 (RSD)≤ 3% ,切割误差为± 5s时分析结果的RSD≤ 4 %。     

A column switching technique for the determination of lidocaine and its metabolites in horse urine

Summary A rapid method is described for the determination of lidocaine and its metabolites in horse urine using a column switching technique and HPLC analysis. This procedure offers a sensitive assay without the need for time consuming extractions.     

Separation of Twenty Biogenic Amines and Derivatives by a High-performance Liquid Chromatographic Column Switching Technique with On-line Fluorimetric and Electrochemical Detections

Abstract

A new high-performance liquid chromatographic technique including the use of an automated column switching system has been developed for the study of dopamine, norepinephrine, epinephrine and serotonin and their related metabolites in biological samples. Through two runs, it has been possible to separate twenty derivatives and three internal standards which have to be added to samples prior to the extraction procedures. In each case, the column switching system allowed to obtain a clear separation of all the compounds, which will be of importance to avoid any expected interference from other endogenous substances, while decreasing the analysis time. By coupling on-line fluorimetric and electrochemical detections the specificity of the technique was enhanced, since the ratio of the responses of both detectors was an index of the purity of the peaks. In addition, fluorimetric detection was found of value to free the determination of some compunds from the effects of solvent front while electrochemical detection increased the sensitivity. Finally, the column switching system allowed a rapid cleaning of the columns between two analyses. A typical application to a human urine sample was shown.     

Column switching-back flushing technique for the analysis of aromatic compounds in gasoline

A simple method, based on the technique of capillary column switching-back flushing, has been developed for the detailed analysis of aromatic compounds in gasoline. The sample was first separated on a 30-m long OV-2330 polar precolumn and then backflushed onto a nonpolar analytical column. The early eluting components from the precolumn and the components of interest (aromatic compounds plus heavier compounds) eluting from the analytical column are all directed to the same flame ionization detection system through a T piece, which permits the quantitative analysis of aromatic hydrocarbons in gasoline by a normalization method using correcting factors. The switching time window of the method is +/-5 s, resulting in easier operation and higher reliability. The reproducibility of the quantitative analysis was < or = 3% RSD for real gasoline samples.     

Determination of S-carboxymethylcysteine in serum by reversed-phase ion-pair liquid chromatography with column switching following pre-column derivatization with o-phthalaldehyde

A method is described for the determination of S-(carboxymethyl)-L-cysteine in serum. After addition of S-(carboxyethyl)-L-cysteine as internal standard, both compounds are extracted into methanol, converted into fluorescent derivatives with o-phthalaldehyde and quantitatively determined by reversed-phase high-performance liquid chromatography. Chromatography of unwanted amino acid derivatives is avoided by column switching, thereby shortening analysis time and increasing column lifetime. The technique was applied in a study of the bioavailability of S-(carboxymethyl)-L-cysteine after oral administration to humans. The concentration-response curve was linear from 2 to 16 micrograms/ml; mean serum concentrations are reported.     

Multidimensional gas chromatography using a double cool-strand interface

Commercial interfaces for multidimensional gas chromatography (MDGC) are based either on a valve or a pneumatic switching between columns. Both exhibit significant drawbacks and only few suppliers exist. An extremely simple interface has been set up to overcome these limitations without requiring any pneumatic control or valves switching. This new MDGC design is based on the cryo-control of the analyte transfer from the first to the second column through two cool strands of a capillary. This technique is simple to implement and does not require any special column connections. Applications involve non-polar/polar phase combinations, as well as chiral analysis, hyphenation to a conventional mass spectrometer, and olfactometric detection. In contrast to conventional MDGC configuration, the present configuration allows the use of a single oven to operate both columns at different temperatures.