• Bulletin of the Korean Chemical Society
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• 제16권4호
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• pp.305-309
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• 1995

The enantiomeric separation of several amino acid derivatives by reversed-phase liquid chromatography using two (R)-and (S)-naphthylethylcarbamate-β-cyclodextrin(NEC-β-CD) bonded stationary phases was studied to illustrate the chiral recognition model of the enantiomeric separation. The retention and enantioselectivity of the chiral separations with (R)-and (S)-NEC-β-CD bonded phases were compared with similar separations with the native β-CD stationary phases. Especially, the enantioselectivity and elution orders between the derivatized amino acid enantiomers are carefully examined. These results can be illustrated by the chiral recognition models involving inclusion complexation, π-π interaction, and/or hydrophobic interaction. Inclusion complexation and hydrophobic interaction of the naphthyl group of the NEC moiety seem to be major chiral recognition components in the enantiomeric separation of 2,4-dinitrophenyl amino acids and dabsyl amino acids on (R)-and (S)-NEC-β-CD columns. For dansyl amino acids, only the inclusion complexation is the dominant factor. Three different chiral recognition models containing π-π interaction, inclusion complexation and hydrogen bonding were proposed for the separation of the 3,5-dinitrobenzoyl amino acid enantiomers, depending on the size and shape of amino acids.

• Bulletin of the Korean Chemical Society
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• 제27권4호
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• pp.589-592
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• 2006

• 분석과학
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• 제7권1호
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• pp.41-52
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• 1994

아미노산 중 alanine, threonine, isoleucine, leucine, aspartic acid, methionine, glutamic acid, tyrosine을 대상으로 열처리, 산처리, UV 광선 조사, 효소(trypsin)의 영향을 살펴보고 6N-HCl, $105^{\circ}C$로 가열했을 때 이성화하는 정도를 측정하였다. 또한 Mass Spectrometer를 이용할 때 각 아미노산의 fragment되는 과정을 조사하여 GC에서 서로 겹칠 때 분석하는 법을 개발하였다. HPLC에서 cyclodextrin bonded phase를 이용해서 dansyl amino acid의 분리를 시도하였다.

• KSBB Journal
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• 제26권4호
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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.

• 한국식품위생안전성학회지
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• 제36권4호
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• pp.347-352
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• 2021

마에는 다양한 기능성 성분이 함유되어 있어서 식용 및 약용으로 다양하게 이용되고 있다. 특히 allantoin은 대표적인 마의 2차 대사산물로서 의약품 및 기능성 화장품 제조에도 활용되는 고부가가치 산물이다. 본 연구에서는 아미노 결합 정지상 HPLC 컬럼을 이용하여 마의 속과 껍질의 allantoin 함량을 분석하였다. Allantoin 표준용액의 검량선의 결정계수(R²)값은 0.9999로 높은 직진성을 보였으며, 검출한계(LOD)와 정량한계(LOQ)는 각각 0.0229 mg/mL 및 0.0694 mg/mL로 설정되었다. 마 속과 껍질의 건조중량 기준 allantoin 함량은 각각 3.09±0.02 mg/g, 3.91±0.11 mg/g으로 속보다 껍질에 더 많은 allantoin이 함유되어있음을 확인하였다. 따라서 이러한 결과를 토대로 향후 농업부산물인 마껍질이 새로운 고부가가치 기능성 소재로 활용될 수 있음을 확인하였다.

• 분석과학
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• 제8권4호
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• pp.859-864
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• 1995

Mono- and oligosaccharides are derivatized with p-aminobenzoic ethyl ester (ABEE), strongly absorbs UV light at 254 nm, in the presence of sodium cyanoborohydride. C18-bonded silica column is used for the separation of sugar-ABEE derivatives in an isocratic mode. RP-HPLC conditions are optimized by using ternary mixture as mobile phase and $45^{\circ}C$ as a column temperature. Sugar-ABEE derivatives are separated well within a short run time (ca. 25 min) by reverse-phase partition chromatographic mode. The ($1{\rightarrow}6$) linkage type of dihexose-ABEE derivatives has shorter retention time than ($1{\rightarrow}4$)-linkage type. After acid hydrolysis of glycoproteins with 2M trifluoroacetic acid, monosaccharide composition and contents are determined. This procedure is very useful for the simultaneous analysis of neutral and amino sugars in a single chromatographic step using RP-HPLC without reacetylation of deacetylated amino sugars, which are produced by acid hydrolysis.

• Bulletin of the Korean Chemical Society
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• 제16권4호
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• pp.344-348
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• 1995

As an effort to elucidate the chiral recognition mechanisms exerted by the (S)-naproxen-derived CSP bearing both π-acidic and π-basic sites, a homologues series of π-basic N-acyl-α-(1-naphthyl)alkylamines and π-acidic N-(3,5-dinitrobenzoyl)-α-amino esters were prepared and resolved. Based on the chromatographic resolution trends of the homologues series of analytes on the (S)-naproxen-derived chiral stationary phase, we proposed chiral recognition mechanisms which demonstrate that the intercalation of the substituent in the analyte molecule between the strands of bonded phase does significantly influence the enantioselectivity for resolving N-acyl-α-(1-naphthyl)alkylamines but the intercalation process is not involved in resolving N-(3,5-dinitrobenzoyl)-α-amino esters.

• Bulletin of the Korean Chemical Society
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• 제32권spc8호
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• pp.3017-3021
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• 2011

Two chiral stationary phases (CSPs) based on (3,3'-diphenyl-1,1'-binaphthyl)-20-crown-6 bonded covalently to silica gel were applied for the first time to the resolution of racemic vigabatrin and its analogue ${\gamma}$-amino acids and the resolution results were compared to those on the commercially available Crownpak CR(+) based on (3,3'-diphenyl-1,1'-binaphthyl)-20-crown-6 coated dynamically onto octadecylsilica gel. While vigabatrin was not resolved at all on Crownpak CR(+), it was resolved quite well on the two CSPs. Among four vigabatrin analogue ${\gamma}$-amino acids, only two were resolved on Crownpak CR(+), but three were resolved on the CSP (CSP 1) containing residual silanol groups and all of four were resolved on the CSP (CSP 2) containing residual silanol group-protecting n-octyl groups. The improved lipophilicity in CSP 2 was proposed to be responsible for its superiority to CSP 1 for the resolution of vigabatrin and analogue ${\gamma}$-amino acids. In addition, the composition of aqueous mobile phase was found to affect the chiral recognition behaviors for the resolution of vigabatrin and analogue ${\gamma}$-amino acids on CSP 2.

• Bulletin of the Korean Chemical Society
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• 제17권12호
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• pp.1117-1123
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• 1996

Chiral recognition models for resolving π-basic N-acyl-α-(1-naphthyl)alkylamines and π-acidic N-(3,5-dinitrobenzoyl)-α-amino alkyl esters on a (S)-tyrosine-derived chiral stationary phase (CSP) containing both π-basic and π-acidic interaction site have been proposed. In the models, the CSP was supposed to interact with the analytes through the π-π interaction between the 3,5-dinitrophenyl or the 3,5-dimethylphenyl group of the CSP and the 1-naphthyl or the 3,5-dinitrophenyl group of the analyte, and through the hydrogen bonding interaction between the appropriate N-H hydrogen of the CSP and the appropriate carbonyl oxygen of the analyte. In this instance, the alkyl substituent of the pertinent enantiomer of the analyte was found to intercalate between the adjacent strands of the bonded phase and consequently control the trends of the separation factors.

• Asian Journal of Atmospheric Environment
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• 제11권4호
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• pp.283-299
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• 2017

An analytical method using high-performance liquid chromatography (HPLC) with fluorescence (FL) detection was developed for simultaneously analyzing 10 polycyclic aromatic hydrocarbons (PAHs) and 18 nitro-derivatives of PAHs (NPAHs). The two-dimensional HPLC system consists of an on-line clean-up and reduction for NPAHs in the 1st dimension, and separation of the PAHs and the reduced NPAHs and their FL detection in the 2nd dimension after column-switching. To identify an ideal clean-up column for removing sample matrix that may interfere with detection of the analytes, the characteristics of 8 reversed-phase columns were evaluated. The nitrophenylethyl (NPE)-bonded silica column was selected because of its shorter elution band and larger retention factors of the analytes due to strong dipole-dipole interactions. The amino-substituted PAHs (reduced NPAHs), PAHs and deuterated internal standards were separated on polymeric octadecyl-bonded silica (ODS) columns and by dual-channel detection within 120 min including clean-up and reduction steps. The limits of detection were 0.1-9.2 pg per injection for PAHs and 0.1-140 pg per injection for NPAHs. For validation, the method was applied to analyze crude extracts of fine particulate matter ($PM_{2.5}$) samples and achieved good analytical precision and accuracy. Moreover, the standard reference material (SRM1649b, urban dust) was analyzed by this method and the observed concentrations of PAHs and NPAHs were similar to those in previous reports. Thus, the method developed here-in has the potential to become a standard HPLC-based method, especially for NPAHs.