胺型键合固定相分离碱性物质的影响因素考察

 以某些碱性物质为探测溶质 ,中性物质乙苯为参照溶质 ,详尽考察了检测温度、缓冲液中阳离子浓度、流动相的流速分别在流动相的 pH值为 3 0和 7 0时对胺型键合固定相分离碱性物质的影响。研究结果表明 ,随着温度的升高 ,碱性物质的保留时间先下降较快 ,然后趋于平缓 ,而柱效和峰形分别得到了提高和改善 ;缓冲液中阳离子浓度对碱性物质的保留行为有较大的影响 ;碱性物质的最佳流速较中性物质小。由于胺型键合固定相中的疏水烷基链中引入了极性官能团氨基 ,因此碱性物质在该固定相上的行为比在传统的固定相上更为复杂。     

Separation of Aminoglycosides by Normal- and Reversed-Phase TLC

JPC – Journal of Planar Chromatography – Modern TLC - The normal-phase (NP) and reversed-phase (RP) thin-layer chromatographic separations of aminoglycosides (streptomycin, kanamycin,...     

Separation of Deoxyribonucleotides Using Ion Suppression High Performance Liquid Chromatography with a Reversed-Phase Column

Abstract

Ion suppression-reversed phase high performance liquid chromatography, using 0.6 M ammonium dihydrogen phosphate as eluent, produces base-line separations of deoxyribonucleotides. The effects of pH and ionic strength are described. This isochratic system is simple, reproducible and fast, requiring less than 30 min for a complete separation, and is suitable for in vitro studies.     

反相毛细管电色谱分离山酮类化合物

目前,毛细管电色谱（CEC）在中草药分析中显示出一些独特的优势,如：CEC流动相相对简单、用量少、峰容量大、更易与质谱（MS）联用。特别是植物提取物中活性成分复杂,需要对色谱峰进行精确的指认并控制峰纯度;采用CEC—MS方法可在线提供中药中各种化合物的质谱图。此外,有许多天然产物在中药中的含量极低,MS的高灵敏度可弥补紫外检测器灵敏度较低的缺陷。因此,研究CEC分离中药成分的选择性问题具有重要的实际意义。蝉翼藤（Securida cainappendiculata Hassk．）为远志科远志族蝉翼藤属攀援灌木,其根茎叶有多种药效,其化学成分主要为黄酮、山酮（XAN）和皂甙。从蝉翼藤中已分离出的10个XAN类成分（结构见图1）。具有显著的抗氧化和保护神经细胞作用。我们曾用毛细管区带电泳（CZE）、高效液相色谱（HPLC）、毛细管胶束电动色谱（MEKC）和毛细管微乳电动色谱（MEEKC）对这10个XAN进行分离,并就电泳条件的变化对分离选择性的影响进行系统研究。本文采用CEC法对这10个XAN成分进行分离,并对其色谱分离条件进行优化研究,以期为今后CEC与MS联用分析中药成分打下基础。     

Reversed-Phase High Pressure Liquid Chromatography Separation of Deuterated Compounds of Biological Importance from Their Protio Analogs

Abstract

A rapid and a practical HPLC method with UV-VIS detection was developed for the separation and analysis of deuterated carotenoids from their protio analogs. Four different chromatography systems were developed. The results showed that with reversed-phase C₁₈ columns it was possible to baseline resolve fully deuterated carotenoids from the nondeuterated analogs. In all instances the deuterated compound eluted ahead of its protio analog indicating that van der Waals forces are operational during the separation process. Specificity, sensitivity, and reproducibility make these methods particularly suitable in plant chemistry for semi-preparative purification processes and methodologies.     

Simple Free Amino Acid Separation by Reversed-Phase Ion-Pair Liquid Chromatography Using Column Switching Technique

Abstract

Reversed-phase ion-pair liquid chromatography with copper (II) ions (RP-IPC-Cu) was applied to develop a high speed separation of free amino acids. Dynamic gradient elution in RP-IPC-Cu could not achieve this purpose due to base line shift, therefore a column switching technique was used with a combination of different alkyl-bonded silica gel columns under isocratic elution. The flexibility of eluent components makes it easy to realize a rapid separation of a mixture of targeted amino acids.     

Separation of Statin-Type Antihyperlipidemic Drugs by Reversed-Phase TLC

JPC – Journal of Planar Chromatography – Modern TLC -     

Reversed-Phase Ion-Pairing Liquid Chromatographic Separation and Fluorimetric Detection of Polyamines

Abstract

A rapid and specific reversed-phase ion-pairing high performance liquid chromatographic procedure for putrescine, spermidine and spermine is reported. The ion-pairing reagent, heptanesulfonate, was employed and o-phthalaldehyde and 2-mercaptoethanol were used for on-line post-column derivatization and subsequent fluorescence detection. Experiments were carried out to determine the effects of several variables such as pH, concentration of the aqueous buffer, counter-ion concentration, and the percentage of organic modifier in the moving phase. The minimum detection limits for the polyamines ranged from 120 pmoles for spermine to 12 pmoles for putrescine. The method includes a gradient program which provides complete separation from amino acids and specificity for the three polyamines. The procedure was applied successfully to urine and serum samples.     

反相色谱法分离氨基苯磺酸和氨基萘磺酸离子性化合物的研究

本文讨论了反相色谱分离氨基苯磺酸,氨基萘磺酸离子性化合物的可行性。所应用的实验条件为检测波长254nm,流动相为10mmol/L 磷酸二氢钠缓冲液(pH=6.98),固定相是C_(18)担体。还讨论了分子结构对保留值的影响。     

Separation of Multiple Ferritin Subunit Types by Reversed-Phase HPLC

Abstract

Subjection of ferritin subunits to reversed-phase HPLC effected a separation of them into three chromatographic species. These three putative subunit species were found in varying proportions from porcine spleen, liver, and heart ferritins as well as human liver, spleen, and placental ferritins. Detailed chemical-physical characterization of each of the isolated species indicate them to be two H-type and one L-type ferritin subunits. Thus, reversed-phase HPLC presently stands as the only available means to separate preparatively the various subunit types of ferritin.     

二氢麦角碱在极性嵌入反相色谱固定相上的分离行为

二氢麦角碱的4种组分具有不同的药效特性,需适当的分析方法对其在不同剂型药品中的含量进行分析.传统液相色谱方法使用强碱性流动相,严重腐蚀硅胶基质色谱填料,影响色谱柱寿命.合成了极性嵌入反相固定相--C18酰胺固定相,并在中性流动相条件下分离4种组分.考察了流动相组成和pH对二氢麦角碱在C18酰胺固定相上保留行为的影响.在150 mm×4.6 mm I.D.的C18酰胺色谱柱上,流动相为乙腈-20 mmol/L Na2HPO4(30:70,V/V,pH 7.0)的条件下实现了4种组分的基线分离.与传统方法相比,极性嵌入反相固定相可以有效的改善碱性化合物的分离特性和大幅度地延长色谱柱的使用寿命.     

Comparison of Normal and Reversed-Phase TLC for Separation of Selected Pesticides

JPC – Journal of Planar Chromatography – Modern TLC - Fifteen urea pesticides have been separated on RP-18WF254 plates with methanol-water and mixed organic (acetonitrile-methanol, 1:1...     

Separation of Bioactive Prostaglandins and their Metabolites by Reversed-Phase Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC - Prostaglandins are biological lipid mediators that control a variety of physiological and pathophysiological processes. They...     

Control of the Selectivity of the Separation of Dicaffeoylquinic Acids in Reversed-Phase Chromatography

Journal of Analytical Chemistry - The chromatographic behavior (change in the logarithm of the retention factor with a change in the composition of the mobile phase) of dicaffeoylquinic (DCQ) acids...     

反相高效液相色谱法制备松果菊苷标准品

 利用反相制备高效液相色谱结合溶剂萃取、大孔吸附树脂柱色谱和葡聚糖凝胶LH 2 0柱色谱方法 ,从管花肉苁蓉的乙醇提取物中纯化制备了苯乙醇苷类化合物松果菊苷的标准品 ,纯度达到 98%以上。方法操作简便 ,重现性好 ,可用于松果菊苷及其他苯乙醇苷类化合物的大量制备。     

柱前手性衍生化反相高效液相色谱法分离拉贝洛尔对映体

以乙酰葡萄糖异硫氰酸酯（GITC）作柱前手性衍生化试剂,用反相高效液相色谱法成功地分离了拉贝洛尔的两对对映异构体,并以荧光检测和紫外检测作对照,确认了4个衍生物的色谱峰。     

反相高效液相色谱法同时测定6种氟喹诺酮类药物

建立了一种反相高效液相色谱-荧光检测法同时测定血浆中6种氟喹诺酮类药物(FQS)的方法。考察了6种FQS的保留值与流动相组成及pH值的关系, 优化了色谱条件及样品前处理方法。确定了以Chira Dex为色谱柱、乙腈-甲醇-Britton-Robinson缓冲液(体积比为73∶7∶20, pH 5.7)为流动相的最佳条件。该法用于血浆样品中FQS的测定,其回收率高于99.0%。该法简便、快速、准确、灵敏度高、重现性好。     

反相高效液相色谱法测定嘌呤、嘧啶类化合物

用反相高效液相色谱法同时分离和测定了胞嘧啶、胸腺嘧啶、腺嘌呤、茶碱和咖啡因等５种结构相似的生物碱基。方法简便、快速,用于茶样中咖啡因的测定,标准加入回收率在９５．６９％～１０４．２０％之间。     

反相液相色谱在蛋白质及多肽分离分析中的应用

反相液相色谱是一种以疏水作用为基础的色谱分离模式。由于它具有分辨率高、重复性好、回收率高等优点,在蛋白质及多肽的分离分析中得到了极为广泛的应用。本文简要介绍了反相液相色谱及其分离机理,对其在蛋白质和多肽研究中的应用如分离纯化、肽图分析、酶活测定、构象变化检测及疏水作用研究等作系统综述,并展望了反相液相色谱在这一领域的发展前景。