用极性固定液改性高聚物PLOT柱的色谱性能研究

 以乙基乙烯苯为单体、二乙烯苯为交联剂，在原位聚合制备的高聚物ＰＬＯＴ柱上用极性固定液ＰＥＧ－２０Ｍ和β，β＇－氧二丙腈进行改性，制备成高聚物气－液－固毛细管柱。通过对柱子热力学参数ｋ＇值的测定，可研究液相在分离过程中的作用及形成气－液－固分离机理所需的液相量。通过制作ｖａｎＤｅｅｍｔｅｒ曲线可研究柱子的动力学特性。发现在形成气－液－固柱后，曲线有明显的拐点，此时是否仍符合Ｇｏｌａｙ方程尚需作进一步的研究。     

用极性固定液改性高聚物PLOT柱的色谱性能研究

以乙基乙烯苯为单体、二乙烯苯为交联剂，在原位聚合制备的高聚物ＰＬＯＴ柱上用极性固定液ＰＥＧ－２０Ｍ和β，β＇－氧二丙腈进行改性，制备成高聚物气－液－固毛细管柱。通过对柱子热力学参数ｋ＇值的测定，可研究液相在分离过程中的作用及形成气－液－固分离机理所需的液相量。通过制作ｖａｎＤｅｅｍｔｅｒ曲线可研究柱子的动力学特性。发现在形成气－液－固柱后，曲线有明显的拐点，此时是否仍符合Ｇｏｌａｙ方程尚需作进一步的研究。     

原位合成分子筛气-液改性毛细管柱的制备与评价

 用原位合成方法成功地制备了一类新型NaA分子筛毛细管柱 ,与传统柱型相比 ,原位合成柱的分子筛层更加均匀与致密、分离效果更佳。在此柱上涂敷不同极性的固定液制备了一类新型气 液分子筛改性SCOT柱 ,测试表明该柱型分离效果较佳、热稳定性好 ,其中超短柱及大口径柱的成功应用更显示该柱型具有很高的实际应用价值 ,值得推广。     

毛细管气液色谱保留过程的研究

以ＰＥＧ２０Ｍ为代表研究了石英毛细管柱气液色谱保留过程,提出了利用毛细管柱测定分配和吸附常数的公式,并测定了９个温度下的分配和吸附常数。计算了８０℃和１２０℃下４支不同液膜厚度柱上吸附对保留的贡献。结果表明,在薄液膜的柱子上界面吸附对保留具有重要贡献;温度升高可以降低弱极性化合物（如正构烷烃和饱和醚）吸附对保留的贡献,但对其它化合物影响不明显。验证了正构烷烃、２－酮系列和正构伯醇的吸附常数的碳数规律。     

一种适用于无程序升温的气液色谱仪的综合填充柱

目前,我国有一半以上的气液色谱仪没有程序升温装置,要在恒温下对不同沸点和不同极性的混合物高效分离,选择理想的柱子就成为一个关键问题,特别是在裂解色谱法中,高聚物裂解出的产物品种多,分子量范围宽,极性大小不一的情况下选择高效分离柱就更为重要。为了克服色谱仪无程序升温装置的缺陷,我们选用了三段串联填充柱,在恒温下能使复杂的裂解产物得到分离,并已成功地用于多种高聚物裂解产物的分离。     

大口径厚液膜毛细管柱的制备

制备出了内径从0.46～0.74mm、液膜厚度从0.9～5.6μm的SE-54大口径厚液膜玻璃毛细管柱,并对它们的性能进行了评价。对低沸点的C_1-C_4烃进行了初步分离。     

分散液液微萃取-气相色谱法测定塑料浸泡液中17种邻苯二甲酸酯

将已粉碎的塑料样品用模拟汗液在37℃下振荡1h。向提取液中加入由丙酮（作分散剂）和四氯化碳（作萃取剂）充分混和的混合液,以3 000r.min-1转速离心5min,分取1μL有机相进样作气相色谱分析。色谱分离时采用HP-5毛细管柱,采用氢火焰离子化检测器进行测定。提取液经上述分散液液微萃取分离富集后测定其中17种邻苯二...     

毛细管电色谱中整体式高聚物毛细管柱技术的进展

对近期毛细管电色谱（CEC）中利用高分子聚合反应制备整体式（monolithic)毛细管柱的技术，特别对各种不同类型的整体式毛细管的制备方法进行了详细介绍；对该类毛细管用于不同样品的分离情况进行了总结。     

冠醚修饰型手性固定液的合成及其气相色谱性能的研究

合成了两种含冠醚功能基的手性固定液：（１Ｓ,２Ｓ）－１－对硝基苯基－２－（４＇－西佛碱基苯并１５－冠－５）－丙烷－１,３－烯丙氧基聚硅氧烷和３－甲基－２－（４＇－甲酰胺－苯并１５－冠－５）－丁酸乙酯。用它们涂制的石英毛细管柱呈强极性,色谱性能良好。并探讨了固定液的结构对分离能力的影响。     

高效邻苯二甲酸二异癸酯毛细管色谱柱的制备

采用超细载体对毛细管柱内壁进行预处理,增加固定液在柱内壁的铺展性,然后将多种复配剂与邻苯二甲酸二异癸酯(DIDP)复配,配制质量浓度为5 mg/mL的固定液,通过加压装置,将固定液通入毛细管柱中,以间甲酚与对甲酚的分离度和对甲酚的理论塔板数评价了复配毛细管柱的分离性能。结果发现:DIDP与SE-54复配效果最好,对甲酚的每米理论塔板数可达3600。建立了快速、简便制备DIDP毛细管柱的方法。     

Determination of Ethosuximide,Phenobarbital, Carbamazepine,Carbamazepine Epoxide and Phenytoin in Serum by high performance liquid chromatography using Radially compressed Columns and an Aqueous methanolic mobile phase

Abstract

A liquid chromatographic method for the determination of antiepileptic drugs in serum is described. The drugs were adsorbed on activated charcoal from which they were recovered by extraction with methylene chloride. The organic extracts were evaporated to dryness and the residues were dissolved in small volumes of the mobile phase. The extracts were clean. Only trace amounts of endogenic compounds were detected. The chromatographic separation was performed with a radially compressed column (C18) that was used daily for several months.     

High-performance liquid chromatography of deferoxamine and ferrioxamine: interference by iron present in the chromatographic system

The assay of the complexed (ferrioxamine) and uncomplexed forms of deferoxamine, a strong iron(III) chelating agent, by reversed-phase high-performance liquid chromatography was investigated. Complex formation with trace amounts of iron in the chromatographic system hinders the assay of deferoxamine by causing appearance of unexpected peaks, reaction zones and variations in retention time. By purging the column with deferoxamine and using EDTA in the mobile phase, these adverse effects in the determination of deferoxamine were eliminated. No interference by iron contamination of the chromatographic system was found in the assay of ferrioxamine, which is facilitated by the strong absorption of the analyte at 430 nm.     

Application of an ovomucoid-conjugated polymer column for the enantiospecific determination of chlorprenaline concentrations in plasma

An ovomucoid-conjugated polymer column was prepared for the liquid chromatographic resolution of racemic compounds. The column showed strong retention of acidic solutes, a characteristic attributed to the structure of the stationary phase support gel. Although the efficiency of the column was lower than that of an ovomucoid-conjugated silica gel column, enantiospecific chlorprenaline determination in plasma was achieved with solute amounts from 1.0 ng to 0.1 microgram.     

Micropacked column gas chromatography with vapour of organic substance as the mobile phase

Summary Retention behaviours of aromatic hydrocarbons were examined by using the vapour of an organic substance as the mobile phase and silica gel as the stationary phase. Gas chromatographic separation of aromatic hydrocarbons was demonstrated by using a system comprising a liquid chromatographic (LC) pump, a micropacked column for LC, a column oven and a UV detector.     

A Stress Stability Behavior and Development of an LC Assay Method for Anastrozole

This present work narrates the stress stability behavior and development of a liquid chromatographic method for the quantitative determination of anastrozole. Anastrozole is appropriately used when using substantial amounts of aromatizing steroids, or when one is prone to gynecomastia and using moderate amounts of such steroids. A chromatographic separation was achieved on a Hichrom RPB18 (250 × 4.6 mm, 5 μ) column using water and mixture of acetonitrile and methanol (1:1 ratio) as mobile phase. Forced degradation studies were performed on bulk samples of anastrozole using acid, base, hydrogen peroxide, heat and UV light. Degradation of the drug substance was observed in base hydrolysis. Degradation product formed under base hydrolysis was found to be Imp-C. The sample solution and mobile phase were found to be stable up to 48 h. The developed method was validated with respect to linearity, accuracy, precision, robustness and forced degradation studies prove the stability indicating power of the method.     

A reversed-phase/hydrophilic interaction mixed-mode C18-Diol stationary phase for multiple applications

A mixed-mode chromatographic packing material, C18 and diol groups modified silica (C18-Diol), was prepared with controllable hydrophobicity and hydrophilicity. It demonstrated excellent aqueous compatibility and stability in aqueous mobile phase; compared to the traditional C18 column, improved peak shape of basic analytes was also obtained. Additionally, it exhibited both reversed-phase liquid chromatographic (RPLC) and hydrophilic interaction chromatographic (HILIC) performance; the analyte separation scope was thus enlarged, demonstrated by simultaneous separation of twenty acids, bases and neutrals. More interestingly, a novel on-line two-dimensional liquid chromatography on the single column (2D-LC-1C) was established by modifying the high performance liquid chromatographic instrument only with the addition of an extra six-port two-position valve. The early co-eluted components of the extract of Lonicera japonica on the 1st-dimension (RPLC) were collected for the online re-injection to the 2nd-dimension (HILIC) by conveniently varying the mobile phase components. Six more peaks were obtained. The established system was simple, easy operation and low cost, which had advantages in analyzing complicated samples.     

Liquid and gas chromatographic separation of isomeric methylated dibenzothiophenes

Trace amounts of a dibenzothiophene (DBT) series in complex matrices were detected by gas chromatography with flame photometric detection (FPD) after purification and isolation by normal-phase high performance liquid chromatography. The gas chromatographic behavior of eleven methylated DBTs was studied on six common stationary phases. Complete resolution of the four monomethyl DBT isomers was only achieved on a capillary column coated with a methylphenylsilicone phase gummified in situ by heat-curing. The determination of the relative distribution of the four monomethylated isomers is proposed as a powerful method for monitoring oil pollution in marine environment.     

高效液相色谱手性固定相法拆分阿折地平对映体

建立了阿折地平对映体的高效液相色谱拆分方法。采用Chiralpak AD-H (250 mm×4.6 mm, 5.0 μm, Daicel公司)手性色谱柱在正相条件下直接拆分阿折地平对映体,考察了固定相种类、流动相组成及柱温等对阿折地平对映体分离的影响。确定了最佳的拆分条件: 流动相为正己烷-异丙醇(90:10, v/v),流速为0.8 mL/min,检测波长为254 nm;柱温为20 ℃;在此条件下阿折地平对映体的分离度为3.3。该法简单快速,重现性好。     

高效液相色谱测定单偶氮染料合成中的原料及中间体

采用高效液相色谱法,对以甲酸铬、4-氯-2-氨基苯酚和2-萘酚为原料合成反应产物单偶氮染料进行分析,以体积比为80∶16∶3∶1的乙腈-水-乙酸-三乙胺为流动相,C18柱为固定相,紫外检测器检测波长为313nm。实验探讨了色谱柱、流动相及pH值等因素对分离效果的影响,确定了最佳色谱条件。该法对甲酸铬、4-氯-2-氨基苯酚、2-萘酚、反应中间体及单偶氮染料的检出限(S/N=3)分别为0.30、0.12、0.17、0.21、0.05g·L-1,这五种组分回收率为95.9%～102.5%,相对标准偏差(RSD)为0.65%～4.16%。该方法简便快速,准确度高,可用于实际生产质量控制分析。