大黄药材指纹图谱研究

采用高效液相色谱法,Hypersil ODS柱,甲醇-1．0%冰醋酸为梯度流动相,研究了大黄的指纹图谱,其中大黄酸、大黄素、大黄酚、大黄素甲醚、芦荟大黄素作为为参照物,并对它们进行了含量测定．检测波长：430nm．共找出了23个共有峰,其中的5个峰是参照物,12个样品之间的相似度在90％以上．样品处理方法简单,研究所得的大黄指纹图谱稳定性、重复性好,可作为大黄药材的特征指纹图谱．     

Characterization of Ethylene methyl methacrylate and Ethylene butylacrylate Copolymers with Interactive Liquid Chromatography

Summary: Copolymers of ethylene with methyl methacrylate (EMMA) and butyl acrylate (EBA), which are of different average chemical composition and block lengths according to NMR analysis, were analyzed by size exclusion chromatography (SEC), differential scanning calorimetry (DSC), Crystallization Analysis Fractionation (CRYSTAF), and high performance liquid chromatography at high temperature (HT-HPLC). With CRYSTAF and DSC crystallizing fractions were detected only in some samples. HT-HPLC fractionated all the samples irrespective of their crystallinity. Homopolymers, PMMA and PE were also found in the copolymer samples of EMMA. EMMA and EBA were separated in HPLC according to the content of polar comonomer. A linear correlation between the MMA content and elution volume could not be established due to the presence of homopolymers as admixtures. In such a case the average chemical composition obtained by NMR does not correspond to the real chemical composition of the copolymers. Unlike EMMA the EBA samples eluted in single peaks, which was used for evaluation of their chemical composition distribution. The comparison of results obtained by fractionation via CRYSTAF and HT-HPLC clearly demonstrates the advantages of the chromatographic approach to study the chemical heterogeneity of olefin based copolymers.     

凝胶色谱净化超高效液相色谱法测定食品中10种工业染料

建立了测定食品中10种工业染料的超高效液相色谱(UPLC)法.样品经提取后,采用凝胶色谱(GPC)净化后收集浓缩,以乙腈-0.1％甲酸溶液为流动相进行梯度洗脱,10种染料得到良好分离.10种染料线性关系良好,相关系数R2＞0.9992,其检出限为0.011～0.049 μg /mL;样品在低、中、高3个加标浓度下,10种染料的回收率为65.0％～107.2％.结果表明该方法适用于食品中10种工业染料的检测,其样品处理方法适用于各类食品,且检测灵敏度高,可实现食品中工业染料的快速测定.     

Determination of Steroids in Human Urine by Micellar Liquid Chromatography

Abstract

A simple and sensitive method for the determination of steroids using micellar liquid chromatography is described. The steroids, including hydroxycorticosterone. corticosterone, northisterone, testosterone, mexdroprogesterone acetate and progesterone, were separated by reversed-phase using a micelles mobile phase following UV detection at 245 nm. The parameters affecting retention of the test solutes such as the concentration of sodium dodecyl sulfate (SDS) and n-butanol-1 in the mobile phase were investigated. It was found that the retention of the solutes was dependent on the composition of mobile phase. The linear calibration plots range from 0.1 to 10 μg ml^?1 in mobile phase containing 5.0 × 10^?2 mol l^?1 SDS/9 % n-butanol-1 at pH 6.0, and the detection limit in order of 0.1 μg ml^?1 was obtained. The proposed method was used for the determination of steroids in urine using direct injection of samples without previous treatment.     

微乳液相色谱法及其应用进展

微乳液相色谱法是使用普通的正相或反相色谱柱,分别以油包水或水包油型微乳为流动相,用常规检测器进行样品分析的液相色谱法。该法具有独特的选择性,能够同时分离极性范围很广的化合物,流动相中的有机溶剂用量少,调节参数多,以及血浆样品可直接进样,梯度洗脱节省再平衡时间等优点,在复杂组分分离方面具有显著的优势。本文对微乳液相色谱法中常用微乳的组成和结构,各组成成分对分离的影响,以及该法的应用进展进行了综述。     

高效液相色谱法同时测定香兰素与邻位香兰素

建立了同时测定香兰素和邻位香兰素的高效液相色谱法.考察了流动相组成、柱温等因素对分析效率的影响.在流动相为5% 乙酸-乙腈(60 :40,体积比),流速1.0 mL/min,柱温25 ℃的优化条件下,香兰素和邻位香兰素可在5 min内实现分离.测定结果表明,香兰素和邻位香兰素在10 ～240 mg/L范围内线性关系良好...     

Pyrolysis Gas Chromatography–Mass Spectrometry for the Characterization of Tire Marks for Forensic Analysis

Pyrolysis–gas chromatography–mass spectrometry was applied to the quantitative and comparative analysis of rubber samples collected from tire marks left on different types of road surfaces. Ten types of tires were used to create skid marks. It was observed that factors such as surface type, sampling method, and the place where the sample was taken revealed no influence on chemical composition of pyrolysate. Chemical analysis of the traces left on different types of substrates allowed one to distinguish between these traces, allocate samples to different rubber classes, and to assign the trace to a particular type of tire. Application of a simple, semi-quantitative method developed to describe the composition of the samples facilitated the distinction between samples. Furthermore, in most cases, tire marks showed great consistency with the rubber taken from the respective tires.     

蛋白质的微乳液毛细管电动色谱分离研究

考察了用微乳液毛细管电动色谱(MEEKC)分离蛋白质时微乳液组成等不同因素对分离的影响,并与胶束电动色谱进行对比,探讨了其分离机理,为蛋白质的分离鉴定提供了一种有力的工具.     

离子色谱法测定水中的高氯酸盐

采用离子色谱法测定了饮用水中痕量的高氯酸盐,以30mmol／LNaOH为淋洗液,1mL／min流量,1000μL进样,在25min内可完成测定高氯酸盐;利用加热浓缩的方法对水样进行前处理,浓缩10倍后进样。结果表明,该法回收率为87．9％,检测限为0．10μg/L,具有实际应用价值。     

反相高效液相三元流动相台阶梯度分离条件的快速优化方法

 根据溶质在柱内的迁移规律 ,建立了一种利用线性梯度实验快速获得溶质保留值方程系数 ,然后以串行响应函数为优化指标进行多台阶梯度分离条件优化的方法。与利用等度实验获得保留值方程的方法相比 ,该法可以大大缩短优化时间。通过该方法对芳香胺和衍生化氨基酸样品进行了分离 ,获得了满意的分离度 ,表明该方法的预测精度很好。     

一种刺松藻来源的硫酸阿拉伯聚糖的制备及特征结构表征

刺松藻(Codium fragile)经水提-醇沉获得粗多糖, 进一步将刺松藻粗多糖(CFP) 通过Q-Sepharose Fast Flow(QFF) 阴离子交换柱纯化得到6个多糖组分CFP1CFP6, 其中, 在CFP6中发现纯度较高的阿拉伯聚糖. 采用高效凝胶渗透色谱与十八角激光散射仪联用法和1-苯基-3-甲基-5-吡唑啉酮(PMP)柱前衍生高效液相色谱法对CFP6的分子量及单糖组成进行了分析. 结果表明, CFP6是一种分子量为79290的多糖, 由阿拉伯糖(Ara)和半乳糖(Gal)组成, 二者摩尔比为14.8:1.0. 通过多维核磁共振波谱、 液相色谱-质谱联用及二级质谱等方法对CFP6的糖苷键连接方式及其寡糖序列结构进行表征, 进一步阐明了该复杂多糖的特征结构. 经判断, CFP6主链由Ara组成, 通过 β-(1→3)糖苷键连接, 在Ara的C2位存在分支结构, 硫酸基位于Ara的C4或C2位.     

离子色谱法同时测定扇贝柱中多种磷酸盐

建立了一种简单、快捷的离子色谱测定扇贝柱中多种磷酸盐的方法。采用超声提取、固相萃取柱净化的方法对样品进行前处理,高容量阴离子交换色谱柱分离,抑制性电导检测器检测。讨论了不同实验条件对多种磷酸盐检测结果的影响。实验证明:磷酸钠检出限为40mg/kg,焦磷酸钠、三聚磷酸钠、三偏磷酸钠均为10mg/kg,回收率在74.8%以上,相对标准偏差(RSD)小于10.7%,实际样品检测结果令人满意。方法具有简便、快捷,选择性好,灵敏度高,无污染、操作步骤简单等优点。     

Simple Multiresidue Determination of Fluoroquinolones in Bovine Milk by Liquid Chromatography with Fluorescence Detection

Abstract

A simple and sensitive method for the simultaneous determination of five fluoroquinolones (ciprofloxacin, enrofloxacin, danofloxacin, difloxacin, and sarafloxacin) in bovine milk was developed. Protein precipitation from milk samples was achieved by the addition of acetonitrile and o‐phosphoric acid. Acetonitrile was removed with dichloromethane, leaving the fluoroquinolones in the acid aqueous extract. The aqueous extract was analyzed by liquid chromatography with fluorescence detection (LC–FD). The mobile phase was composed of acetonitrile and 10 mM citrate buffer solution of pH 4.5, with an initial composition of acetonitrile‐water (12∶88, v/v) and using linear gradient elution. Norfloxacin was used as an internal standard. The limits of detection found ranged from 1 to 6 ng · mL^?1 and were below the maximum residue limits (MRLs) established by the European Union. The proposed method was applied to the determination of these compounds in different bovine milk samples. Method validation was carried out by a recovery assay.     

Determination of Pesticides in the Rhizome of Traditional Chinese Medicines by Gas Chromatography with Electron Capture Detection

A simple and efficient gas chromatography method for the determination of 27 organochlorine and pyrethroid pesticides in traditional Chinese medicine was developed. Pesticide residues were extracted from the samples by oscillation and ultrasound, and purified by gel permeation chromatography and florisil solid phase extraction. The analysis was performed by gas chromatography with micro-electron capture detection. The purification conditions, such as the extraction and elution solvents, extraction methodology, and gel permeation chromatography conditions, were optimized. Traditional Chinese medicines were purified by different methods based on their composition. Under optimized conditions, the calibration graph was linear from 10 to 500 µg/L and the correlation coefficients varied from 0.9958 to 0.9997. The detection limits of these pesticides were between 0.09 and 1.82 µg/kg. The recovery of the pesticides spiked in various samples at four concentrations ranged from 73.2% to 106.4%, with relative standard deviations between 1.0% and 14.0%. This study indicates that the method is useful for determining pesticides in rhizome traditional Chinese medicines.     

基于色谱方法的煤沥青指纹图谱构建

煤沥青成分极其复杂,其中含有分子量较大的多环芳烃及其氧化产物等组分。不同来源的原料煤及生产工艺得到的煤沥青在芳构化程度、组成、性质、分子结构等方面皆差别很大。该文分别采用气相色谱-质谱(GC-MS)、裂解/气相色谱-质谱(Py/GC-MS)和高效液相色谱(HPLC)手段,为煤沥青指纹图谱库的构建发展了普适、稳定、简单的分析方法。在GC-MS方法中采用常用的HP-5MS柱,在线性温度梯度条件下分析,得到33个组分的色谱图,方法对不同样品的稳定性良好。采用裂解/气相色谱-质谱方法研究探讨了较高温度下组分结构和组成的变化,对于沥青产品的加工以及老化研究具有借鉴意义。在HPLC方法建立过程中,采用最常用的C_(18)柱反相色谱分离模式,以甲醇/水为流动相,在线性梯度条件下建立方法,针对不同样品可以得到41个组分的稳定色谱峰。基于该文的方法,可为进一步建立煤沥青的指纹谱图库,以及进一步完善煤沥青的评价方法,开发煤沥青的新用途提供理论基础数据。     

反相高效液相色谱法分离测定烟草中的多酚类化合物

对植物中9种多酚类化合物的色谱分离条件进行了优化,分别探讨了流动相组成、流动相中醋酸浓度、醋酸溶液与甲醇的比例对保留时间的影响,确定了梯度分离条件,并对9种天然多酚类化合物进行了定量分析。该方法的检测限为13.26~59.29 mg/kg (S/N=3)。在3.0～100.0 mg/L 范围内呈良好的线性关系,相关系数r2为 0.9979~0.9999。9种待测化合物的加标回收率为96.8%~108%,相对标准偏差(RSD)小于3.8% (n=3)。用80%甲醇超声提取烟草样品,并通过优化的色谱条件对其进行分析,测定了实际烟草样品中芸香苷和绿原酸的含量。结果表明,该方法具有一定的实用价值。     

蛋白质分离色谱填料及其特性

将载体按其化学组成分类，综述蛋白质色谱填料的进展。文中还讨论了键合固定相、多孔复合材料和混合载体等新型复合材料不同的制备方法以及这些载体在层析过程中的主要特性。     

Enantiomeric Separation of Amino Alcohols by Ion-pair Chromatography

Many drugs or physiologically important compounds are chiral molecules and the optical isomers of them may differ in their pharmacological activities. In some instances differences in undesirable side-effects of these enantiomers are important. So the separation of chiral compounds is becoming increasingly important. Liquid chromatography (LC) is well known as an excellent method for separating and analyzing mixtures of stereoisomers. For resolving the ionic chiral compounds it is available t…     

Comparison of Micellar Electrokinetic Chromatography with HPLC for the Separation of Hematoporphyrin Derivatives

ABSTRACT

A mixed SDS micelle and BSA buffer system was used in the micellar electrokinetic chromatography (MEKC) separation of hematoporphyrin derivatives (HPD) at pH 8.0 with untreated capillaries. The effects of altering the composition of sodium dodecyl sulfate (SDS) electrolyte solution on the separation efficiency of the hematoporphyrin derivatives were presented. The results show that separation efficiencies were enhanced by using a mixture of SDS and BSA. The results demonstrated that CE methodology can compete with well-established techniques such as HPLC for the separation of biomedical and pharmaceutical samples with regard to time and expense of analysis.     

用反相高效液相色谱法测定片剂中西特那非的含量

建立了反相高效液相色谱测定伟哥中有效成分西特那非(sildenafil)含量的方法, 方法快速、灵敏、准确, 重复性好, 平均回收率为100.4%, 应用该法对不同片剂中西特那非的含量进行了测定.