共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
流动相组成对外消旋阿苯达唑亚砜对映体拆分的影响 总被引:2,自引:0,他引:2
涂敷直链淀粉-三(3,5-二甲基苯基氨基甲酸酯)(ADMPC)于自制的球形氨丙基硅胶上,制备了一种手性固定相。采用高效液相色谱法(HPLC),在正相条件下用该固定相直接拆分了广谱驱虫药物阿苯达唑的代谢产物阿苯达唑亚砜(albendazole sulfoxide, ABZSO)的外消旋对映体。系统地选用了多种二元及三元流动相体系对样品进行拆分,结果表明,流动相中不同种类的醇改性剂及其含量的不同对样品的保留时间和立体选择性有不同程度的影响,甲醇、乙醇等作改性剂用于拆分样品的效果较好;采用三元流动相体系正己烷- 相似文献
3.
Shao-hua Huang Zheng-wu Bai Chuan-qi Yin Shi-rong Li 《高分子科学》2006,(2):107-114
Two polyurethanes of different molecular weights were prepared by the copolymerization of phenyl diisocyanate and diisopropyl tartrate. The polyurethanes having terminal isocyanate groups were reacted with 3-aminopropyl silica gel to afford two chiral stationary phases. The Mn of the two polyurethanes were 4057 g/mol and 6442 g/mol. The polyurethanes and the corresponding chiral stationary phases were characterized by FT-IR, 1H NMR and elemental analysis. The loading capacities of the polyurethanes on silica gel were 0.68 mmol units/g and 0.61 mmol units/g, respectively. The separation performance and the influence of additives, triethylamine and trichloroacetic acid, on the separation of chiral compounds were investigated by HPLC. The chiral stationary phase prepared from polyurethane with Mn of 4057 g/mol demonstrated better enantioseparation capability than that with Mn of 6442 g/mol. Additionally, it was found that the addition of triethylamine and trichloroacetic acid in the mobile phases significantly improved the enantioseparation for these two chiral stationary phases. 相似文献
4.
Structural optimization of a chiral selector for use in preparative enantioselective chromatography 总被引:2,自引:0,他引:2
Utilizing the immobilized-target strategy, the structure of a proline-derived chiral stationary phase was optimized for use in the preparative chromatographic separation of the enantiomers of two chiral selectors used in commercial chiral stationary phases. In this study, various N-acylated proline anilides were prepared and chromatographed on the commercial Pirkle-1J and -Burke 2 chiral stationary phases. The analyte which displayed the greatest retention without sacrifice of enantioselectivity (the 3,5-dimethoxyanilide of N-undecenoyl proline) was chosen for incorporation into the preparative chiral stationary phase. Once prepared, this phase shows increased analyte retention and enantioselectivity comparable to that of earlier phases derived from 3,5-dimethyl anilides of proline. The increased retention allows one to use mobile phases in which the target analytes are more soluble, hence greatly facilitating an increase in the through-put of a column of a given size. 相似文献
5.
Karin Balmr Bengt-Arne Persson Per-Olof Lagerstrm 《Journal of chromatography. A》1994,660(1-2):269-273
The enantioselective separation of omeprazole on different chiral stationary phases was investigated. The two enantiomers could be resolved on three different phases with immobilized protein, Chiral-AGP, Ultron ES-OVM and BSA-DSC, employing aqueous mobile phases with 2-propanol as organic modifier. On Chiralpak AD, an amylose-based chiral stationary phase, the enantiomers of omeprazole and three analogues could be separated using a non-polar hexane-ethanol mobile phase. For omeprazole the retention order was reversed when 2-propanol was replaced with ethanol or methanol as the modifier of hexane in the mobile phase. 相似文献
6.
7.
Chiral stationary phases (CSPs) for high-performance liquid chromatographic (HPLC) have been prepared by coating silica gel with cellulose tribenzoate or cellulose trisphenylcarbamate. The effect of chiral additives on preparation of the CSPs was studied with (+)-l-mandelic acid, (−)-2-phenyl-1-propanol, (+)-1-phenyl-1,2-ethanediol and (−)-1-(1-naphthyl)ethanol as chiral additives for cellulose tribenzoate and (−)-2-phenyl-1-propanol and (+)-phenylsuccinic acid as chiral additives for cellulose trisphenylcarbamate. The results showed that chiral recognition by these stationary phases was increased in comparison with the original CSPs, especially the resolution (R
S) obtained. The method can be used to improve the efficiency of enantiomer separation by silica gel stationary phases coated with polymers. 相似文献
8.
9.
将纤维素-三(3,5-二甲基苯基氨基甲酸酯)(CDMPC)涂敷于自制的球形氨丙基硅胶上,制备成了纤维素-三(3,5-二甲基苯基氨基甲酸酯)手性固定相(CDMPC-CSP)。利用正相高效液相色谱,在该固定相上对新合成的4种吲哚类衍生物对映体进行了手性拆分。通过选择不同结构和浓度的醇类改性剂,优化了色谱分离条件,同时探讨了醇的结构和浓度对于对映体拆分和保留的影响。结果表明,适合Ⅱ~Ⅳ号样品拆分的醇类改性剂分别为正丁醇、乙醇和乙醇,而适合Ⅰ号样品的醇类改性剂为乙醇和正丙醇组成的混合体系。在优化的各流动相体系下,4种吲哚类衍生物的对映体都得到了很好的分离。在此基础上计算了它们的对映体过量值(e.e.值)。实验结果令人满意,表明高效液相色谱手性固定相法是拆分这类化合物的一种理想方法。 相似文献
10.
Azido cellulose phenylcarbamate (AzCPC) was synthesized regioselectively and chemically immobilized onto aminized silica gel to afford urea-bonded chiral stationary phases (CSPs). The obtained CSPs showed good enantioselectivity in HPLC towards various racemates using normal phase eluants (hexane/2-propanol, hexane/chloroform or hexane/2-propanol/chloroform). 相似文献
11.
绕轴旋转180°能与自身重合的C_2对称型手性化合物在手性催化和手性分离领域有重要应用。以L-脯氨酸苯基酰胺衍生物为手性源,合成了一类新型的C_2对称型手性固定相,并进行了手性色谱拆分评价。与单侧链取代的刷型固定相进行对比,C_2对称型手性固定相对所评价的31种酸性、中性和碱性分析物表现出更好的手性选择性。考察了固定相末端苯环上的取代基团对手性拆分的影响,综合来看,苯环上无取代基的C_2对称型手性固定相的分离性能最优。对某些手性对映体,C_2对称型手性固定相的分离因子随温度的增高而呈现异常增大的现象,表明了其有别于单侧链取代的固定相的分离机理。该类新型手性固定相的提出对进一步丰富刷型手性固定相的种类和拓展其应用具有重要意义。 相似文献
12.
键合纤维素(4-甲基苯甲酸酯)手性固定相的制备及其手性拆分 总被引:3,自引:0,他引:3
采用包夹聚合法,将硅小球同硅烷化试剂反应制得乙烯基硅胶,然后将该乙烯基硅胶同经十一烯酰氯、4-甲基苯甲酰氯衍生的纤维素共聚,制备出含不同官能团的聚合物包夹硅基的键合型纤维素(4-甲基苯甲酸酯)类手性固定相。分别以正己烷异丙醇、正己烷四氢呋喃为流动相,对此键合型手性固定相的手性识别能力进行了评价。为了与同类型的涂敷型纤维素(4-甲基苯甲酸酯)手性固定相作比较,合成了涂敷型纤维素(4-甲基苯甲酸酯)手性固定相。结果表明,键合型纤维素(4-甲基苯甲酸酯)手性固定相具有一定的手性识别能力,可以拆分所研究的6种手性化合物中的4种。 相似文献
13.
14.
Evaluation of differences between Chiralpak IA and Chiralpak AD‐RH amylose‐based chiral stationary phases in reversed‐phase high‐performance liquid chromatography
下载免费PDF全文
![点击此处可从《Journal of separation science》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Polysaccharide‐based chiral stationary phases can be used for the enantioselective separation of a wide range of structurally different compounds. These phases are available with chiral selectors coated or immobilized on silica gel support. The means of attachment of the chiral selector to the carrier can influence the separation performance of these stationary phases. This paper deals with evaluation of differences in the separation abilities of coated Chiralpak AD‐RH versus immobilized Chiralpak IA amylose‐based stationary phases in the reversed–phase mode of high–performance liquid chromatography. A set of chiral analytes was separated under acidic and basic conditions. Differences were observed in the enantioseparation potential of the tested phases. The linear‐free energy relationship and additional evaluation of ionic interactions were used to ascertain whether the interactions that participate in retention and enantioseparation are affected by the means of preparation of these phases. All the interactions covered by the linear‐free energy relationship were significant for the studied phases and their absolute values were almost always higher for the coated phase. Ionic interactions were found to be more important on the immobilized stationary phase but did not contribute to any improvement in the enantioselective separation performance. 相似文献
15.
A new single‐urea‐bound 3,5‐dimethylphenylcarbamoylated β‐cyclodextrin chiral stationary phase and its enhanced separation performance in normal‐phase liquid chromatography
下载免费PDF全文
![点击此处可从《Electrophoresis》网站下载免费的PDF全文](/ch/ext_images/free.gif)
《Electrophoresis》2018,39(2):348-355
A new single‐urea‐bound chiral stationary phase based on 3,5‐dimethylphenylcarbamoylated β‐cyclodextrin was prepared through the Staudinger reaction of mono (6A‐azido‐6A‐deoxy)‐per(3,5‐dimethylphenylcarbamoylated) β‐cyclodextrin and 3‐aminopropyl silica gel under CO2 atmosphere. The new phase exhibited good enantioseparation performance for 33 analytes using normal‐phase HPLC conditions; 19 of them were baseline separated. Effects of structure of analytes, alcoholic modifiers, and acidic/basic additives on separation performances of this new cyclodextrin chiral stationary phase have been studied in detail. The results showed that the retention and resolution of acidic and basic analytes on the CSP were greatly affected by the additives. Peak symmetry for some analytes could be improved by simultaneously adding acidic and basic additives to the mobile phase. This work expands the potential applications of the cyclodextrin‐based chiral stationary phases in the normal‐phase HPLC. 相似文献
16.
17.
Liang Zhao Yongfei Ming Hongli Zhang Shengxiang Jiang 《Journal of Analytical Chemistry》2009,64(8):795-805
A new chiral stationary phase of 3,5-dimethylphenylcarbamates of cellulose chemically bonded to 3-aminopropyl silica gel was
prepared, which may be used with a wide range of solvents including standard and non-standard ones. Several racemic indole
derivatives have been resolved using standard and non-standard solvents on the immobilized chiral column (15 cm × 0.46 cm)
at a flow rate of 1.0 mL/min or 0.5 mL/min with a UV detection at 230 nm. Separation of indole derivatives on immobilized
and coated chiral stationary phases (CSP) in HPLC using a mixture of hexane/2-propanol as mobile phase was compared. The resolution factors for immobilized and coated
chiral column were 0.57–2.02 and 0.61–4.03, respectively. It was found that both coated and immbolized chiral stationary phases
were suitable for the separation of indole derivatives; however, the coated CSP possesses a higher resolving power than the
immobilized one.
The article is published in the original. 相似文献
18.
在以正己烷-异丙醇为移动相的体系中,用ChiralpakAD和ChiralcelOD作为手性固定相对15种乙炔基氮杂环丙烷类化合物对映体进行了HPLC手性拆分。这些化合物至少在一支柱上能基线级分离。 相似文献
19.
20.
纤维素-三(3,5-二甲基苯基氨基甲酸酯)涂敷手性固定相的制备、表征及评价 总被引:3,自引:0,他引:3
以纤维素和 3,5 二甲基苯基异氰酸酯为原料合成了纤维素 三 (3,5 二甲基苯基氨基甲酸酯 ) ,并采用两种不同的方法将其涂敷于小粒径 (平均粒径 5 μm ,平均孔径 13nm ,比表面积 110m2 / g)的氨基丙烷化硅胶 (APS)上 ,制得了在纤维素 三 (苯基氨基甲酸酯 )类衍生物涂敷的硅基手性固定相中具有较佳手性识别能力的固定相。通过元素分析、扫描电子显微镜对两种手性固定相进行了表征 ,用高效液相色谱法对两种固定相的手性拆分能力进行了评价和比较。 相似文献