• Analytical Science and Technology
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• v.22 no.2
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• pp.148-151
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• 2009

Enantiomer separation of N-fluorenylmethoxycarbonyl (FMOC) $\alpha$-amino acid was performed on covalently immobilized chiral column (Chiralpak IB) based on polysaccharide derivative as a chiral selector by reversed phase liquid chromatography. The effect of the reversed mobile phase on the chromatographic parameters of the enantioselectivities, resolution factors and retention times using covalently immobilized Chiralpak IB was shown. Also the enantiomer separation of N-FMOC $\alpha$-amino acid in the reversed and normal phase was compared and the results obtained in the former mobile phase were generally lower than those in the latter mobile phase.

• KSBB Journal
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• v.19 no.4
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• pp.263-268
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• 2004

The separation method using chiral stationary phase in preparation of chiral compound was wildly used, but in this work, supercritical fluid chromatography was suggested in the stability to resolve the chiral mixtures. To determine the optimum operating condition of the racemic ibuprofen, the retention factor and resolution with change in pressures, temperatures and the contents of IPA % (vol.) in CO$_2$ were investigated. The retention factor was decreased with increase in pressure and decrease in temperature. The factor was also influenced by the content of IPA in mobile phase, while the resolution was worse with a increase in IPA %. From the experimental results, the desirable separation condition was 130 bar, 311.15 K and 4% IPA in CO$_2$. Compared to the asymmetric peak shape by liquid chromatography, that of supercritical fluid chromatography was symmetric which was a favorable condition for preparative separation.

• Analytical Science and Technology
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• v.23 no.1
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• pp.97-101
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• 2010

(R)-N-3,5-dinitrobenzoyl (DNB) phenylglycinol derived chiral selector was used as a HPLC chiral stationary phase (CSP) for the resolution of racemic N-acylnaphthylalkylamines. In this study, determination of optical purity was performed by both chiral chromatography and NMR spectroscopy by using the (R)-phenylglycinol derived chiral selector. The data of accuracy and precision of each optical purity value are calculated from the results of NMR and HPLC experiments by comparing with true value. Average error of the NMR method was +2.2% with average RSD of 4.54%, while that of HPLC method was -3.5% with average RSD of 3.23%.

• Journal of the Korean Chemical Society
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• v.39 no.2
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• pp.94-102
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• 1995

S-Hydroxypropyl(PH) ${\beta}$-cyclodextrin(hydrophilic), dialkyl(DA)-cyclodextrin(hydrophobic), trifluoroacetyl(TA) ${\gamma}$-cyclodextrin(intermediate) stationary phases were used for gas chromatographic separation of racemic alcohols and their derivatives. All the alcohols used for this experiment were derivatived by using trifluoro acetic anhydride, acetic anhydride, or trichloro acetic anhydride. It is apparent that the enantioselectivity of the enantiomeric pairs was very dependent on the type of acylation reagent. The best experimental condition of optical resolution of the alcohols and their derivatives was different on the polarity of the solute molecules. The chiral separation was also studied depending on temperature, polarity of the column, and hydrogen bonding ability and steric effect between the alchols and CD stationary phase. The chiral recognition mechanism is dependent not upon the kinds of the chiral stationay phases but upon the derivatization of the racemic alchols.

• KSBB Journal
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• v.18 no.4
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• pp.261-265
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• 2003

Ibuprofen was analyzed by chiral high performance liquid chromatography. Retention behaviours of the standard mixtures of ibuprofen were investigated to obtain their acceptable resolution. A chromatographic column (3.9 ${\times}$ 300 mm) was packed by Kromasil CHI-TBB packings (10 $\mu\textrm{m}$) and n-hexane was used as a mobile phase with 0.1％ acetic acid and tert-butyl methyl ether. Isocratic elution of ibuprofen at 1.0 $m\ell$/min was performed by changing the mobile phase compositions. The experimental variables affecting the resolution were the compositions of mobile phase and chemical buffer (n-hexane and tert-butyl methyl ether). The resolution between the enantiomers were correlated into the several types of empirical equations including linear form, and their agreements between experimental data and calculated values were examined by the regression coefficient.

• Analytical Science and Technology
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• v.24 no.5
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• pp.360-367
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• 2011

Optical purities of 10 commercialized naproxens prepared from eight Korean drug companies were examined by an optimized chiral HPLC condition. The Chiralcel OD-H column and ChiralHyun-LE(S)-1 column were used as chiral stationary phases and the mixed eluent of hexane/isopropanol/acetic acid as 100:2.85:0.1 was used as a mobile phase for effective enantioseparation. Optical purity values of most samples were higher than 97 percents, only one of them was about 95 percents. The average relative standard deviation of them appeared very small (0.034%).

• KSBB Journal
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• v.26 no.4
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• pp.323-327
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• 2011

The convenient derivatization method of chiral amino alcohols as 9-anthraldimine Schiff base derivatives for chiral resolution was developed and the liquid chromatographic enantiomer separation of chiral amino alcohols as 9-anthraldimine derivatives was investigated on several coated and covalently bonded polysaccharide-derived chiral stationary phases (CSPs). In general, the performance of Chiralcel OD-H (or Chiralcel OD) (${\alpha}$ = 1.24-2.89), the coated CSP derived from cellulose derivative was superior to the other CSPs for resolution of 9-anthraldimine derivatives of several amino alcohols. The results of enantioseparation depending on the structure of 9-anthraldimine analytes like the steric bulky group and the polar moiety etc were discussed. The analytical method was applied to measure the enantiomeric purity of commercially available chiral amino alcohols. It is expected that the convenient analytical method will be very efficient for determination of enantiomeric purity of amino alcohols as 9-anthraldimine Schiff base derivatives with strong UV absorption.

• KSBB Journal
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• v.27 no.4
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• pp.232-236
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• 2012

Comparative liquid chromatographic enantiomer separation of ${\alpha}$-amino acids, their esters and primary amino compounds was performed using two chiral stationary phases (CSPs) prepared by covalently bonding (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid (18-C-6-TA) of the same chiral selector. In general, the separation factors and resolution factors for these analytes on CSP 1 were greater than on CSP 2, while these capacity factors on CSP 2 were quite greater than on CSP 1. Except for leucine methyl ester and phenylalanine methyl ester, the elution orders of all analytes including ${\alpha}$-amino ${\alpha}$-alkyl acids and phenylglycine alkyl esters on CSP 1 are identical to those on CSP 2. This study showed that different connecting structures for these two CSPs might influence their ability to resolve the analytes depending on their structures related to the chiral recognition mechanism.

• KSBB Journal
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• v.20 no.3
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• pp.177-182
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• 2005

Simulated moving bed (SMB) chromatography was used in the petrochemical industry in the 1960s and its use has been widened to separate chiral compounds in the 1990s. Chiral stationary phase (CSP) is the key component in SMB for the separation of the chiral compounds. CSP has been developed for the analytical use in HPLC, however, its development successfully adapted for the preparative use in SMB chromatography. This review covers the present state-art technology of CSP for SMB chromatography in terms of selectivity, stability, and capacity.

• Journal of the Korean Chemical Society
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• v.34 no.4
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• pp.345-351
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• 1990

Optical isomers of DABS-amino acids have been separated in a reversed phae high performance liquid chromatography by adding Cu (Ⅱ)-L-Proline chelate to the mobile phase. The retention behaviors for the DABS-amino acids are discussed in terms of pH of the mobile phase and the concentrations of acetonitrile, Cu (Ⅱ) complex, and buffer. The selectivity of the optical isomers of DABS-amino acids increases with the pH of the mobile, and the concentration of the chelate, but decreases with concentration of the oganic modifier. The concentration of buffer does not affect the optical separation selectivity. A separation mechanism is illustrated by cis and trans formation based on the steric effect of the ligand exchange reaction between DABS-amino acids and the copper chelate.