Simultaneous determination of geniposide and its metabolites genipin and genipinine in culture of Aspergillus niger by HPLC

When cultivated with Aspergillus niger, geniposide, an important drug, is transformed into genipin and genipinine. A simple and rapid HPLC method for simultaneous determination of geniposide and its two metabolites in broth of A. niger is described. The chromatographic separation was achieved on a C18 ODS column (250 x 4.6 mm) by gradient elution with 0.1% formic acid in water and 0.1% formic acid in acetonitrile as the gradient mixtures. The flow rate was 1 mL/min, the detection wavelength was 238 nm and the column temperature was kept at 28 degrees C. The retention times of geniposide, genipin and genipinine were 10.9, 13.8 and 21.5 min, respectively. The mean absolute recoveries of three analysts were over 98%. Quantification limits were 0.01 microg/mL for geniposide and 0.02 microg/mL for the two metabolites. The method was applied for the quantification of geniposide, genipin and genipinine during fermentation and the evaluation of the bioavailabilities of these three compounds in Caco-2 monolayer.     

血水草生物碱的HPLC分离

建立了内衬聚亚胺型Ｃ１８ 反相高效液相柱分离血水草生物碱ＨＰＬＣ 新方法。 考察了梯度洗脱分离时,起始缓冲液组成及ｐＨ 值对分离的影响。 当用０ ．０２８ ｍｏｌ／Ｌ Ｋ２ ＨＰＯ４（ｐＨ ８ ．５） 为起始洗脱液, 线性梯度洗脱至１００ ％ 甲醇时, 血水草提取液中主要生物碱以及含量较少的生物碱可得到理想分离。 用峰面积归一化法考察不同地点, 不同季节血水草各生物碱含量的变化规律, 为血水草的采收提供了科学依据。     

Crystallization Elution Fractionation and Thermal Gradient Interaction Chromatography. Techniques Comparison

Summary: The chemical composition distribution has been shown to be the most critical and discriminating parameter in understanding the performance of industrial polyolefins with non homogeneous comonomer incorporation. The chemical composition distribution is being analyzed by well known techniques such as temperature rising elution fractionation, TREF, crystallization analysis fractionation, CRYSTAF and crystallization elution fractionation, CEF. These techniques separate according to crystallizability and provide a powerful and predictable separation of components based on the presence of branches, irregularities or tacticity differences, independently of the molar mass. TREF, CRYSTAF and CEF can not be used, however, for the separation of more amorphous resins, and may not always provide the best solution for complex multi-component resins due to the existence of some co-crystallization. The application of high temperature interactive HPLC to polyolefins opened a new route to characterize these types of polymers. The use of solvent gradient HPLC for separation of polyethylene and polypropylene and the developments in HPLC on carbon based columns extended further the application of high temperature HPLC in polyolefins. A new approach has been developed recently using the carbon based column but replacing solvent gradient by a thermal gradient which facilitates the analysis of polyethylene copolymers and provides a powerful tool for the analysis of elastomers. Thermal gradient interaction chromatography (TGIC) is being compared with TREF and CEF with the analysis of model samples. The advantages/disadvantages of each technique are being investigated and discussed. The combination of TGIC and TREF/CEF provides an extended range of separation of polyolefins.     

液相色谱梯度淋洗过程中溶剂的分布规律

在液相色谱梯度淋洗过程中,由于柱外过程和流动相在柱内的输运过程中的延迟作用和扩散的影响,使得溶剂浓度梯度变化时,在柱内特定位置的浓度随时间的变化符合相应的分布规律.本文从理论和实验两个方面对这一规律加以探讨,并讨论了仪器条件对该分布规律的影响.     

五加生化胶囊的高效液相色谱指纹图谱研究

应用高效液相色谱(HPLC)法建立五加生化胶囊的指纹图谱。采用ANGLAVenusil XBP-C18色谱柱(250×4.6mm,5μm),以甲醇-0.1%磷酸溶液为流动相,梯度洗脱,检测波长为327nm,五加生化胶囊多数峰达到基线分离。采用2004A中药色谱指纹图谱相似度评价系统对11批样品的指纹图谱进行峰匹配,确定12个共有峰,11批五加生化胶囊指纹图谱的相似度均在0.90以上。结果表明:五加生化胶囊的HPLC指纹图谱特征性和专属性强,可较系统地用于五加生化胶囊的质量控制。     

液相色谱中的半峰宽规律

本文介绍通过相同组分、不同配比冲洗剂等度和梯度冲洗样品的实验,首次发现在液相色谱中,溶质的色谱峰半宽度与保留值间存在同一线性关系;在梯度冲洗时流出组分的色谱峰半宽度与虚拟保留值间同样存在线性关系。该结果证明,我们提出的组分在柱末端有相近的以长度为量纲的谱带半宽度的正确性,同时该结果对梯度最佳分离条件的预测亦很有益。     

Quality evaluation of Ganoderma through simultaneous determination of nine triterpenes and sterols using pressurized liquid extraction and high performance liquid chromatography

A method combining HPLC and pressurized liquid extraction was developed for simultaneous quantification of nine components, including eight triterpenes (ganoderic acid A, ganoderic acid Y, ganoderic acid DM, ganoderol A, ganoderol B, ganoderal A, methyl ganoderate D and ganoderate G) and a sterol (ergosterol), in Ganoderma. The determination was achieved by using a Zorbax ODS C18 analytical column (4.6 x 250 mm id, 5 microm) and gradient elution with diode-array detection. All calibration curves showed good linearity (r2 > 0.9997) within the test ranges. The developed method showed good repeatability for the quantification of the nine investigated components in Ganoderma with intra- and inter-day variations of less than 2.4% and 4.1%, respectively. The validated method was successfully applied to quantify the nine components in two species of Ganoderma, i.e. G. lucidum and G. sinense, used as Lingzhi in China. Furthermore, hierarchical clustering analysis based on the nine components in HPLC profiles from the tested 11 samples showed that chemical characteristics were significantly different between G. lucidum and G. sinense, which suggested that clinical investigation should be performed so as to ensure the safety and efficacy of medication.     

Solvent delivery in the new application areas of high-performance liquid chromatography

Summary The development of new column packings for biological macromolecules, as well as the techniques for handling micropacked columns, sets new demands on solvent delivery systems for HPLC. The main implications of these developments with respect to pump design are discussed and the evaluation of a solvent delivery system (pump and gradient programmer) optimized for these purposes is presented.Presented at the 14th International Symposium on Chromatography London, September, 1982     

Identification of triacylglycerols by high-performance liquid chromatography-gas-liquid chromatography and liquid chromatography-mass spectrometry

Triacylglycerols from rat adipose tissue were chromatographed by high-performance liquid chromatography (HPLC), with a gradient of propan-2-ol in acetonitrile as the mobile phase. Fractions of the material eluting from the column were collected and analysed by automated gas - liquid chromatography of the fatty acid methyl esters obtained after transmethylation. Triacylglycerols were identified by using a combination of their fatty acid content and elution time from the HPLC column. Fractions corresponding to whole peaks or groups of peaks were also collected and re-chromatographed on a liquid chromatography - mass spectrometry system equipped with a belt interface. For most triacylglycerols, good agreement was obtained between the two methods, although mass spectrometric identification of the early eluting peaks was complicated by poor resolution of the triacylglycerols on the HPLC system.     

山蜡梅叶颗粒的高效液相色谱指纹图谱定性及定量分析

应用高效液相色谱法建立可同时对山蜡梅叶颗粒进行鉴别和有效成分含量测定的色谱指纹图谱。以Cosmosil C18色谱柱为分离柱,甲醇与甲酸混合溶液进行梯度洗脱,检测波长为365 nm。成分芦丁、槲皮素和山奈素的质量浓度均与峰面积呈线性关系,线性范围分别为4.6~110.4,1.0~24.0,1.5~36.0 mg.L-1。运用中药色谱指纹图谱相似度评价系统2004版进行分析,20批样品平均相似度为95%以上。颗粒剂中三个成分的含量分别为芦丁含量(130±20)μg.g-1,槲皮素含量(35±10)μg.g-1,山奈素含量(60±10)μg.g-1。建立的山蜡梅叶颗粒的色谱指纹图谱,为质量控制提供新方法。     

高效液相色谱法分析啤酒花浸膏中的6种酸性成分

建立了啤酒花浸膏中6种酸性成分(合葎草酮、葎草酮、加葎草酮、合蛇麻酮、蛇麻酮、加蛇麻酮)的高效液相色谱分析方法.分别考察了酸的加入、有机相种类及柱温对色谱分离效果的影响.在室温条件下,以Hypersil ODS2柱(250 mm ×4.6 mm,5 μm)为分析柱,以乙腈-0.1％(v/v)磷酸水溶液(pH 2.2)(...     

Numerical modeling of elution peak profiles in supercritical fluid chromatography. Part I—Elution of an unretained tracer

When chromatography is carried out with high-density carbon dioxide as the main component of the mobile phase (a method generally known as “supercritical fluid chromatography” or SFC), the required pressure gradient along the column is moderate. However, this mobile phase is highly compressible and, under certain experimental conditions, its density may decrease significantly along the column. Such an expansion absorbs heat, cooling the column, which absorbs heat from the outside. The resulting heat transfer causes the formation of axial and radial gradients of temperature that may become large under certain conditions. Due to these gradients, the mobile phase velocity and most physico-chemical parameters of the system (viscosity, diffusion coefficients, etc.) are no longer constant throughout the column, resulting in a loss of column efficiency, even at low flow rates. At high flow rates and in serious cases, systematic variations of the retention factors and the separation factors with increasing flow rates and important deformations of the elution profiles of all sample components may occur. The model previously used to account satisfactorily for the effects of the viscous friction heating of the mobile phase in HPLC is adapted here to account for the expansion cooling of the mobile phase in SFC and is applied to the modeling of the elution peak profiles of an unretained compound in SFC. The numerical solution of the combined heat and mass balance equations provides temperature and pressure profiles inside the column, and values of the retention time and efficiency for elution of this unretained compound that are in excellent agreement with independent experimental data.     

Application of HPLC column-switching in pesticide residue analysis

Summary An overview is given of the applicability of HPLC with column-switching in pesticide residue analysis. The main advantage of HPLC with column-switching is the enhancement of both sensitivity and selectivity combined with a high potential for automation. The selection of optimal conditions such as column dimensions, mobile phase compositions and multi step gradient elution is discussed.     

色谱累加进样分离实验条件的研究

在采用反相液相色谱或亲和色谱完成蛋白质等大分子分离时,根据溶质保留值随溶剂梯度变化曲线上突变点的差别,可以通过累加进样分离法进行样品制备或直接柱内富集分析,但这一方法并非在任意条件下、对任何样品都适用。该文根据不同形式的保留值方程从理论上探讨了样品保留值与进样时间差、梯度洗脱速率等实验条件之间的关系;结果表明：两次进样的出峰时间差与进样时间间隔成正比关系,也与其在等度情况下的容量因子有关。样品中的两种组分在间隔进样时的流出时间差主要由两组分的容量因子决定,当样品中存在两种以上保留性能相近组分时,若保证指定的分离度,进样时间间隔存在一极大值,超出该范围,分离条件将不能满足     

How to generate peak capacity in column liquid chromatography. The Halász nomograms revised

For the separation of complex samples it is necessary to run the analyses on a chromatographic set-up with high peak capacity. The concept of peak capacity is broader than the one of the theoretical plate numbers because it covers both the column characteristics and the run time of the separation. Therefore, a desired peak capacity can be obtained with many combinations of particle diameter, column length, pressure, and analysis time: either with a short column, small-diameter packing, short analysis time, and high pressure; or with less pressure at the expense of a longer column, larger-diameter packing, and longer analysis time. These combinations can be presented in the form of nomograms with the analysis time as x-axis and the peak capacity as y-axis and including particle diameter, column length, and pressure as parameters. The practical limits of the peak capacity are given by the maximum pressure delivered by the pump in use. These considerations are valid for isocratic and gradient separations as well. They are based on a 1982 paper by Halász and G?rlitz and apply the concept of HPLC columns used at their Van Deemter optimum.     

银黄口服液的质量控制及其高效液相色谱指纹图谱的研究

利用高效液相色谱方法,建立了复方银黄口服液及其原料药材黄芩和金银花的指纹图谱,测定了银黄口服液中黄芩苷 和绿原酸的含量。以Lichrospher C18色谱柱(250 mm×4.6 mm i.d.,5 μm)为分离柱,以甲醇和0.1%磷酸水溶液为流动 相进行二元梯度洗脱,流速0. 6 mL/min,在254 nm波长下检测。采用夹角余弦和相关系数的方法,计算6批银黄口服液指 纹图谱的相似度均在0.99以上,表明银黄口服液的质量未见显著差异。将银黄口服液指纹图谱中的共有峰与原料药材黄芩 和金银花的指纹图谱中的共有峰相比较,对其归属进行确认,大部分共有峰可以匹配。     

红花中红花黄色素含量的反相高效液相色谱测定

本文分离纯化了红花（Carthamus tinctorius L）中Safflower yellow A，Safflomin A，Safflower yellow B，Safflomin C四种红花黄色素，并用所纯化的红花黄色素做标准品，用反相高效液相色谱法，梯度洗脱，同时测定了不同产地红花中四种红花黄色素的含量。该方的法准确度高，重现性好。     

任意多阶程序升温优化程序用于氨基酸对映体的分离

用氨基酸对映体在手性毛细管柱上扮离作实例, 研究了任意多阶程升优化程序的普遍适用性. 按计算结果进行实验所得的实际色谱图证明, 优化程序的应用将有助于在保证分离度的前提下, 大大缩短分析时间.提出了一种可以大体反映程序升温下复杂样品各组分在柱内运动过程的轨迹图(x-t图).轨迹图上所显示的每一组分在到达行程终点的时间的准确性得到了色谱实验的验证, 从而为探讨物质在各种条件下的柱内运动状,况特别是为多维色谱的深入研究提供了可能性.