对氨基苯胂酸及其氧化物的色谱研究

用紫外分光光度计分析了对氨基苯胂酸（PABAA）及其氧化物的光谱特征后,在十八烷基键合相硅胶柱上,以甲醇-缓冲液作流动相,研究了二者的容量因子随流动相离子强度、柱温、甲醇含量变化的规律。用季铵盐作离子对试剂,反相离子对色谱法分离PABAA时,分离机理符合高子对机理,在适当条件下,所试验的化合物都可有所保留。对保留值作出贡献的有固定相排阻作用、分配作用以及居次要地位的PABAA与固定相表面剩余硅醇基的相互作用。排阻作用及分配作用的相对重要性与流动相中甲醇和离子对试剂的浓度有关。     

唑来膦酸及其有关化合物的反相离子对高效液相色谱分离

采用反相离子对高效液相色谱法研究了唑来膦酸及其有关化合物的色谱分析与分离方法。优化的分离条件：以Hypersil C8柱为固定相,以甲醇-5 mmol/L磷酸二氢钠缓冲液(含6 mmol/L四丁基溴化铵溶液,用氢氧化钠溶液调节pH至7.0)(体积比为20∶80)为流动相,等度洗脱,流速为1.0 mL/min,紫外检测波长为220 nm,柱温为室温。在该色谱条件下,唑来膦酸与有关化合物(包括其合成过程中残余的原料咪唑乙酸和其他氧化分解产物)的分离良好,与保留时间最接近的杂质峰的分离度大于2.5。该方法不需进     

Reversed-Phase Ion-Pair High-Performance Liquid Chromatography of Phosphatidylinositols

Abstract

Reversed-phase ion-pal, high-performance liquid chromatographic (HPLC) separations of molecular species of phosphatidylinositols (PI) were studied. Mobile phases of acetonitrile-methanol-water containing various tetraalkylammonium phosphates (TAAP) were used for optimization. Stationary phases of macroporous polystyrene divinylbenzene (MPD), octylsilica, and octadecylsilica exhibited arying degrees of retentivity toward PI solutes. Without exception capacity factors (k') of PI on either alkylsilica or MPD increased with the alkyl chain length and the concentration of the quaternary ammonium counter ions evaluated. the results can be interpred in terms of an ion-pair retention mechanism. Logarithmic k' values were linearly related to the total number of carbons in TAAP. Perbenzoylation of PI yielded derivatives readily resolvable without the use of any mobile phase additive. Incorporation of TAAP to a mobile phase facilitated component separations of early-eluting perbenzoates. In HPLC with     

反相离子对色谱法测定油菜籽（饼）中的硫苷

 用反相离子对色谱法直接测定油菜籽（饼）中原 始硫苷成分,在样品预处理中加入抗氧化剂以防止吲哚类硫苷的氧化分解。研究了主要色 谱参数对硫苷组分保留值和选择性的影响,采用烯丙基硫苷或苯甲酸作内标,对硫苷的6种 组分进行了定性定量的测定。     

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.     

Separation of Nucleic Acid Constituents by Column Liquid Chromatography

As a general rule the electrophoretic mobility of molecules and particles is solely governed by the potential at their surface of shear (ζ-potential) and does not depend on their size or shape. There are hawever two sets of exceptional conditions under which the size or shape of molecules and particles may influence their electrophoretic mobility. These are:

1) Conditions under which the ratio between the dimensions of the molecules or particles and the thickness of their diffuse ionic double layer is such that the distortion of the electric field by the particles is neither at its minimum nor at its maximum.

2) Conditions under which the molecules or particles are migrating under the influence of an electric field inside a porous medium, the size of the pores of which is such that they impede the larger molecules or particles more than the smaller ones.     

Determination of Amino Acid Enantiomers in Pharmaceuticals by Reversed-Phase High-Performance Liquid Chromatography

Precolumn derivatization with the reagent o-phthalic aldehyde/N-acetyl-L-cysteine (OPA/NAC) was used for the determination of amino acid enantiomers by reversed-phase high-performance liquid chromatography. The influence of the composition and pH of the eluent on the separation of the resulting derivatives was studied with the example of four amino acids. It was found that the highest selectivity and efficiency of the separation of OPA/NAC derivatives of amino acids is attained with the use of the eluent methanol–0.01 M Na₂HPO₄ (pH 6.0). The optimum composition of the mobile phase and conditions of the gradient elution were selected for the separation of a mixture of 20 amino acid derivatives. A procedure was developed for the determination of amino acid enantiomers in parenteral nutrition preparations. The procedure was used for the determination of D-isomers of arginine, alanine, methionine, phenylalanine, and leucine in the preparation Polyamine.     

Ion-Pair Reversed-Phase Thin-Layer Chromatography and High-Performance Liquid Chromatography of Benzoic Acids

The separation of benzoic acids by ion-pair reversed-phase thin-layer chromatography and high-performance liquid chromatography was studied. In the optimization of separation conditions, the effect of the nature and concentration of the organic solvent, acidity of the mobile phase, concentration of salts of quaternary ammonium bases, and the length of their hydrocarbon radical on the retention of benzoic acids was studied. Conditions of the separation of a mixture of benzoic, hydroxybenzoic, aminobenzoic, and nitrobenzoic acids on Silufol plates impregnated with cetyltrimethylammonium bromide were selected; the mobile phase was isopropanol–ammonium acetate buffer solution with pH 5–dodecyltrimethylammonium bromide.     

反相离子对高效液相色谱法快速分离和定量测定食品中的甜蜜素

采用反相离子对高效液相色谱法快速分离和测定食品中的甜蜜素。在ODS柱上,以V（甲醇）：V（水,含离子对试剂）=30：70的溶液为流动相进行分离,分别考察了流动相中离子对试剂和甲醇浓度对甜蜜素保留行为的影响。检测波长为205nm;采用外标法定量,测得甜蜜素在0．5～2．5g／L范围内具有良好的线性关系;回收率在96．9％～101．7％之间;检测限为0．05g／L。     

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。     

离子对试剂用于4种水溶性维生素的液相色谱分离

1　引　　言在进行复合维生素药物分析、饲料添加剂维生素混料及饲料复合维生素制剂的分析时 ,通常会遇到几种高浓度水溶性维生素的分离问题 ,而这些水溶性的维生素则是有酸性、中性、碱性化合物混合的 ,例如Ｖｃ、ＶＢｌ、ＶＢ2 、ＶＢ6等。常规的反相色谱法通过改变流动相的ｐＨ值 ,离子强度 ,有机相浓度 ,及分离湿度等条件来优化这类复杂物质的分离 ,但其适应范围往往很窄。本文则将简述离子对试剂戊烷磷酸钠 (ＰＩＣＢ5)、己烷磷酸钠 (ＰＩＣＢ6)和庚烷磷酸钠 (ＰＩＣＢ7)用于水溶液性维生素Ｖｃ、ＶＢ1 、ＶＢ2 、ＶＢ6的分离 ,结果令…     

反相离子对高效液相色谱法测定心肌组织中的三磷酸腺苷

 采用反相离子对高效液相色谱法测定心肌组织中三磷酸腺苷 (ATP)的含量。样品经高氯酸溶液沉淀蛋白 ,上清液用KOH溶液中和后用反相离子对高效液相色谱法分离测定。色谱柱为SpherisorbODS2柱 ,流动相为甲醇 KH2 PO4缓冲液 (内含 5mmol/LIPR A离子对试剂 ) ,在 2 59nm波长处检测。方法最低检测限为 2mg/L,在 5mg/L～ 1 0 0 mg/L范围内有良好的线性关系 (r=0 9998) ,方法的回收率为 97 8%～ 1 0 4 % ,日内精密度 <4 85% ,日间精密度 <8 81 %。方法准确、灵敏、快速 ,适用于动物和人心肌组织中ATP含量的测定。     

反相硅胶整体柱离子对色谱法快速测定吡啶离子液体阳离子

建立了整体柱离子对色谱-紫外检测法梯度淋洗快速分离测定4种吡啶离子液体阳离子的方法。分离采用C18反相硅胶整体柱,以离子对试剂(用柠檬酸调节pH值)-乙腈为淋洗液,并采用多级梯度洗脱程序。实验考察了色谱柱、离子对试剂、乙腈浓度、色谱柱温度及流速对吡啶阳离子保留的影响,并讨论了其保留规律。咪唑阳离子的保留符合碳数规律。最佳色谱条件是:在流速3.0 mL/min,柱温30℃下,以1.0 mmol/L庚烷磺酸钠(pH 4.0)(A)+乙腈(B)为淋洗液进行梯度洗脱。淋洗梯度为0～2.0 min,10%B;2.0～2.5 min,10%～15%B;2.5～4.0 min,15%B;4.0～4.5 min,15%～20%B;4.5～10.0 min,20%B。在此条件下,4种吡啶阳离子可在7 min内基线分离。所测阳离子的检出限(S/N=3)为0.05～0.17 mg/L;峰面积的相对标准偏差(n=5)小于0.6%。将本方法用于实验室合成的离子液体样品和污水样品的分析,加标回收率在95.7%～99.0%之间。本方法准确、快速,具有较好的实用性。     

Determination of Hydroxy-2-ethylenediaminetriacetic Acid (HEEDTA) and Fe-HEEDTA in Nutrient Solutions by Ion-Pair Reversed-Phase High-Performance Liquid Chromatography

A reversed-phase ion-pair liquid chromatography method for the accurate detection and determination of hydroxy-2-ethylenediaminetriacetic acid (HEEDTA) and Fe-HEEDTA has been developed. Three mobile phases containing 0.05 M tetrabutylammonium hydroxide, 0.05 M tetrabutylammonium bromide, or 0.05 M tetrabutylammonium bromide + phosphate buffer were employed in this method. Iron was added to each mobile phase after addition of the selected ion pair reagent to determine the amount of HEEDTA in both the free and/or the metal chelated forms at concentrations as low as 50 μM. The method depends on the formation of the iron chelate with HEEDTA in the mobile phase at pH 7. Calculation of the amounts of chelated HEEDTA with iron in the mobile phase was verified using the Geochem-PC computer program, which showed that 99.95% of HEEDTA was chelated to iron at pH 7.     

Enantiomeric Separation of N-Protected Non-Protein Amino Acid Esters by Chiral High-Performance Liquid Chromatography

Abstract

We have found that high-performance liquid chromatographic analysis of enantiomeric N-protected amino acid esters on a cellulose tris(3,5-dimethylphenylcarbamate) chiral stationary phase column (Daicel Chiralcel OD) can be utilized as one of the procedures for determining the optical purities of non-protein amino acids. The methyl esters of the N-benzyloxycarbonyl (Z) derivatives of a number of non-protein amino acids showed excellent to good enantiomeric separations using hexane - 2-propanol as a mobile phase. There was a regularity in the elution order of enantiomers: the L-isomer had a shorter retention time than the D-isomer. We have also investigated the effect of the N-protecting groups and the ester groups on the enantiomeric separation. The Z, 4-methoxybenzyloxycarbonyl (Z(OMe)), and 9-fluorenylmethoxycarbonyl (Fmoc) derivatives gave exceptionally good resolutions. By contrast, the formyl and t-butoxycarbonyl (Boc) groups impaired the enantiomeric separation. Almost all the alkyl esters examined and the benzyl ester gave resolutions better than or of the same order as the methyl ester. The resolution of β-amino acids was worse than that of the corresponding α-amino acids.     

Determination of Imidazolium Ionic Liquid Cations by Ion-Pair Chromatography Using a Monolithic Column and Direct Conductivity Detection

Determination of four imidazolium ionic liquid cations by ion-pair chromatography was carried out using direct conductivity detection. Chromatographic separations were performed on a silica-based monolithic column with 1-heptanesulfonic acid sodium + acetonitrile + citric acid as eluent. Carbon number rule and influence of acetonitrile on the retention of imidazolium cations were discussed. Detection limits (S/N = 3) for the cations were 2.1–55.9 mg L^?1. Relative standard deviations (RSD, n = 5) for peak areas were less than 3.0%. The method has been successfully applied to the determination of two ionic liquids synthesized by organic chemistry lab.     

Urinary Uric Acid Determination by Reversed-Phase High Pressure Liquid Chromatography

Abstract

Reversed-phase high pressure liquid chromatography with UV detection was proven to be a powerful method for the separation and quantitation of urinary uric acid. We have compared three different treatments for urine samples previous chromatographic injection: alkaline methanol extraction, ethylacetate extraction and centrifugation. It was also studied storage conditions for urine samples.

Our findings show that the method has high specificity and reproducibility for urinary uric acid. Samples are stables and require only centrifugation previous injection to the chromatograph.     

反相液相色谱用球形共聚物柱填料

采用新颖聚合工艺制备用于反相高效液相色谱柱填料的乙基苯乙烯-二乙烯苯球形共聚物,不需使用备有高速搅拌的混匀器和特殊的筛析设备,聚合物粒径的95％在3～7μm之间,测算了渗透性、柱效和峰不对称性等柱参数,并通过分离实例说明该填料对胺类、酚类和芳烃类具有优良分离性能。