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手性高效液相色谱固定相 总被引:11,自引:1,他引:11
手性高效液相色谱固定相达世禄徐伟董亚琼(武汉大学化学系武昌430072)1848年,Pasteur借助显微镜从外消旋体酒石酸铵钠盐分离其对映体,首次实现光学异构体分离。100多年来,用化学、生物化学等方法分离对映体的操作繁杂、速度慢、效率低[1]。1... 相似文献
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Wang F Yeung D Han J Semin D McElvain JS Cheetham J 《Journal of separation science》2008,31(4):604-614
We report the application of column temperature programs as a tool to examine unusual temperature-induced behaviors of polysaccharide chiral stationary phases (CSPs). Using dihydropyrimidinone (DHP) compounds as probes we observed the heating (10-50 degrees C) and cooling (50-10 degrees C) van't Hoff plots of retention factors and/or selectivities of DHP compounds were not superimposable on AD, IA, and AS-H columns solvated with ethanol (EtOH)/n-hexane (n-Hex) mobile phases. The plots were not superimposable on AD, IB, and AS-H columns solvated with 2-propanol (2-PrOH)/n-Hex mobile phases. The thermally induced path-dependant behaviors were caused by slow equilibration as evidenced by the disappearance of the hysteresis in the second heating to cooling cycle and in a cooling to heating cycle. From the step-temperature program (10-50-10 degrees C), only EtOH solvated AD and AS-H phases showed the change of retention factors and/or selectivities with time while only 2-PrOH solvated AS-H phase showed similar behaviors. 相似文献
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Roberto Dallocchio Alessandro Dessì Barbara Sechi Bezhan Chankvetadze Giorgi Jibuti Sergio Cossu Victor Mamane Paola Peluso 《Electrophoresis》2023,44(1-2):203-216
In this study, the enantioseparation of 14 planar chiral ferrocenes containing halogen atoms, and methyl, iodoethynyl, phenyl, and 2-naphthyl groups, as substituents, was explored with a cellulose tris(4-methylbenzoate) (CMB)-based chiral column under multimodal elution conditions. n-Hexane/2-propanol (2-PrOH) 95:5 v/v, pure methanol (MeOH), and MeOH/water 90:10 v/v were used as mobile phases (MPs). With CMB, baseline enantioseparations were achieved for nine analytes with separation factors (α) ranging from 1.24 to 1.77, whereas only three analytes could be enantioseparated with 1.14 ≤ α ≤ 1.51 on a cellulose tris(3,5-dimethylphenylcarbamate) (CDMPC)-based column, used as a reference for comparison, under the same elution conditions. Pendant group–dependent reversal of the enantiomer elution order was observed in several cases by changing CMB to CDMPC. The impact of analyte and chiral stationary phase (CSP) structure, and MP polarity on the enantioseparation, was evaluated. The two cellulose-based CSPs featured by different pendant groups were also compared in terms of thermodynamics. For this purpose, enthalpy (ΔΔH°), entropy (ΔΔS°) and free energy (ΔΔG°) differences, isoenantioselective temperatures (Tiso), and enthalpy/entropy ratios (Q), associated with the enantioseparations, were derived from van ’t Hoff plots by using n-hexane/2-PrOH 95:5 v/v and methanol/water 90:10 v/v as MPs. With the aim to disclose the functions of the different substituents in mechanisms and noncovalent interactions underlying analyte–selector complex formation at molecular level, electrostatic potential (V) analysis and molecular dynamics simulations were used as computational techniques. On this basis, enantioseparations and related mechanisms were investigated by integrating theoretical and experimental data. 相似文献
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The separation of enantiomers by chromatographic methods, such as gas chromatography, high‐performance liquid chromatography and capillary electrochromatography, has become an increasingly significant challenge over the past few decades due to the demand of pharmaceutical, agrochemical, and food analysis. Among these chromatographic resolution methods, high‐performance liquid chromatography based on chiral stationary phases has become the most popular and effective method used for the analytical and preparative separation of optically active compounds. This review mainly focuses on the recent development trends for novel chiral stationary phases based on chitosan derivatives, cyclofructan derivatives, and chiral porous materials that include metal‐organic frameworks and covalent organic frameworks in high‐performance liquid chromatography. The enantioseparation performance and chiral recognition mechanisms of these newly developed chiral selectors toward enantiomers are discussed in detail. 相似文献
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Liming Peng Swapna Jayapalan Bezhan Chankvetadze Tivadar Farkas 《Journal of chromatography. A》2010,1217(44):6942-6955
Three polysaccharide-derived chiral stationary phases (CSP) were evaluated for the resolution of more than 200 racemic compounds of pharmaceutical interest in the reversed-phase (RP) separation mode. The population of test probes was carefully evaluated in order to insure that it covers as completely as possible all structural diversity of chiral pharmaceuticals. RP showed the highest potential for successful chiral resolution in HPLC and LC/MS analysis when compared to normal phase and polar organic separation modes. Method development consisted of optimizing mobile phase eluting strength, nature of organic modifier, nature of additive and column temperature. The newer CSPs, cellulose tris(3-chloro-4-methylphenylcarbamate) and amylose tris(2-chloro-5-methylphenylcarbamate), were compared to the commonly used cellulose tris(3,5-dimethylphenylcarbamate) in regards to their ability to provide baseline resolution. Comparable success rates were observed for these three CSPs of quite complimentary chiral recognition ability. The same method development strategy was evaluated for LC/MS analysis. Diethylamine as additive had a negative effect on analyte response with positive ion mode electrospray (ESI+) MS(/MS) detection, even at very low concentration levels (e.g., 0.025%). Decreasing the organic modifier (acetonitrile or methanol) content in the mobile phase often improved enantioselectivity. The column temperature had only a limited effect on chiral resolution, and this effect was compound dependent. Ammonium hydrogencarbonate was the preferred buffer salt for chiral LC with ESI+ MS detection for the successful separation and detection of most basic pharmaceutical racemic compounds. Ammonium acetate is a viable alternative to ammonium hydrogencarbonate. Aqueous formic acid with acetonitrile or methanol can be successfully used in the separation of acidic and neutral racemates. Cellulose tris(3-chloro-4-methylphenylcarbamate) and amylose tris(2-chloro-5-methylphenylcarbamate) emerge as CSPs of wide applicability in either commonly used separation modes rivaling such well established CSPs as cellulose tris(3,5-dimethylphenylcarbamate). Screening protocols including these two new CSPs in the preferentially screened set of chiral columns have higher success rates in achieving baseline resolution in shorter screening time. 相似文献
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将邻乙酰水杨酸纤维素酯通过间隔臂--2-(3,4-环氧环己基)乙基三甲氧基硅烷键合于硅胶之上,制得键合型手性固定相CSP1,考察了其与同类纤维素衍生物制得的涂敷型手性固定相在拆分效果方面的异同,并探讨了其差异的原因与机理。为了印证间隔臂中环己基对于手性拆分的作用,本文又将CSP1与间隔臂中不具有环己基的键合型手性固定相CSP2进行了拆分对比,进一步证实了间隔臂中环己基的作用。结果表明,键合型手性固定相相比涂敷型固定相在拆分咪唑类药物方面具有优势,这种优势一方面来自于流动相范围的扩大,另一方面是由于间隔臂中环己基对纤维素表面结构的修饰作用。 相似文献
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《Journal of separation science》2017,40(8):1710-1717
Natural and regenerated chitins were derivatized with 3,5‐dimethyphenyl isocyanate. The corresponding chiral stationary phases were prepared by coating the resulting chitin derivatives on 3‐aminopropyl silica gel. The swelling capacity of the chitin derivatives, enantioseparation capability, as well as eluents tolerance of the chiral stationary phases were evaluated. The results demonstrated no remarkable difference in enantioseparation capability between natural and regenerated chitins based chiral stationary phases. The similar enantioseparation characteristics of two chiral stationary phases could be understood by comparing the IR spectra of related chitin derivatives. The one of the two chiral stationary phases prepared by coating the chitin derivative with a lower molecular weight generally provided better enantioseparations. All chiral stationary phases can work in 100% chloroform, 100% ethyl acetate, 100% acetone, and the mobile phases containing a certain amount of tetrahydrofuran. The chiral stationary phase prepared from the chitin derivative with the highest swelling capacity exhibited better enantioseparations than others. This chiral stationary phase was damaged by flushing with 100% tetrahydrofuran, however, the enantioseparation capability was recovered again after the column was allowed to stand for 1 month. Furthermore, the recovered chiral stationary phase provided better enantioseparations for some chiral analytes than before. 相似文献
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Xianghua LaiSiu-Choon Ng 《Tetrahedron letters》2003,44(13):2657-2660
A novel cyclodextrin derivative: mono(6A-N-allylamino-6A-deoxy)perphenylcarbamoylated β-cyclodextrin was synthesized. Hydrosilylation with (EtO)3SiH and then reaction of the reactive siloxane with pristine silica gel afforded a facile entry into a durable, structurally well-defined chiral stationary phase capable of enantioseparation of a variety of racemic drugs. 相似文献