Effect of apolar diluents on the behavior of chiral stationary phases in gas chromatography.  Binary mixtures of N-lauroyl-L-valine-tert-butylamide with squalane and n-tetracosane

Watabe, Katsunori; Gil‐Av, E.; Hobo, Toshiyuki; Suzuki, Shigetaka

doi:10.1021/ac00177a010

Cited by 12 publications

(5 citation statements)

References 24 publications

(29 reference statements)

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“…Up to now, the techniques employed for chiral separation mainly involved chromatography such as HPLC [1], GC [2], micellar MEKC, and capillary gel electrophoresis (CGE) [3,4]. However, these separation processes make it hard to predict the elution order of enantiomers and often have a poor selectivity for enantiomers.…”

Section: Introductionmentioning

confidence: 99%

Selective adsorption of D‐ and L‐phenylalanine on molecularly‐imprinted polymerized organogels formed using polymerizable gelator N‐octadecyl maleamic acid

Zhang

Wang

et al. 2008

J of Separation Science

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The polymerizable gelator N-octadecyl maleamic acid (ODMA) can self-assemble in selected polymerizable organic solvents, such as 2-hydroxyethyl methacrylate (HEMA) and methylacrylic acid (MAA) to form thermally stable polymerizable organogels. A mixture consisting of HEMA and MAA as the monomer and functional monomer, PEG dimethacrylates (PEG200DMA) as the crosslinker, BOC-L-phenylalanine (BPA) or L-phenylalanine ethyl ester (PEE) as the chiral templates, was gelatinized by ODMA firstly and subsequently polymerized by in situ UV irradiation or thermal initiation. The molecularly imprinted polymerized organogels were obtained after the removal of the templates through ethanol extraction. Selective adsorption of D- and L-phenylalanine was performed on the polymerized organogels. The results indicate rather high adsorption efficiency obtained for L-phenylalanine compared with that for D-phenylalanine, which was found to be dependent on the concentrations of ODMA, content of template, and the method of polymerization. Herein, the concentration of ODMA in the organogels played an important role for the adsorption efficiency of D- and L-phenylalanine.

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Section: Introductionmentioning

confidence: 99%

Selective adsorption of D‐ and L‐phenylalanine on molecularly‐imprinted polymerized organogels formed using polymerizable gelator N‐octadecyl maleamic acid

Zhang

Wang

et al. 2008

J of Separation Science

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“…Gil-Av and Hobo reported enantioseparation with N-lauroyl-L-valine-tert-butylamide by GC. [11,12] Dobashi et al reported on extended scopes of ennatiomer resolution with chiral diamide phases in LC. [13] Previous works in our laboratory studied the immobilization method of diamide-type CSPs and examined their enatioselectivies.…”

Section: Introductionmentioning

confidence: 99%

A new diamide‐type chiral stationary phase for chiral resolution by normal and reversed phase HPLC

Chen

Fuyumuro

Nakagama

et al. 2003

Journal of Liquid Chromatography & Related Technologies

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In this work, a new diamide-type chiral stationary phase was developed by chemically bonding the N-stearoyl-L-leucine on the aminopropylsilica gel. It has been successfully used for the chiral resolution of the benzoyl-, dinitrobenzoyl-, and trifluoroacethyl amino acids in the modes of normal phase, as well as for the underivatized amino acids in the mode of reversed phase. It was found that the hydrogen bonding makes significant contribution to the chiral resolution. It has been demonstrated that the chiral resolution, by the use of diamide-type chiral stationary phase (CSP), can be achieved without the p-p interaction between the CSP and analytes.

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“…The binary stationary phase consisted of the diamide N-lauroyl-L-valinetert-butylamide mixed with either squalane or tetracosane 3,4 and the solutes separated were N-trifluoroacetyl(TFA)-R-amino acid isopropyl esters. Purnell and co-workers 5 have found that in many systems GC retention on a binary phase can be expressed by eq 1, even if weak interactions, the extent of which should change with composition, can be expected in the binary phase.…”

Section: Introductionmentioning

confidence: 99%

“…In two recent publications , the correlation of the gas chromatographic retention volume of hydrogen-bonding solutes with the weight fraction of a self-associating polar solvent, diluted by an apolar component, was discussed. The binary stationary phase consisted of the diamide N -lauroyl- l -valine- tert -butylamide mixed with either squalane or tetracosane , and the solutes separated were N -trifluoroacetyl(TFA)-α-amino acid isopropyl esters. Purnell and co-workers have found that in many systems GC retention on a binary phase can be expressed by eq 1, even if weak interactions, the extent of which should change with composition, can be expected in the binary phase.…”

Section: Introductionmentioning

confidence: 99%

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Dependence on Composition of GC Retention on a Self-Associating Solvent/Hydrocarbon Mixture: Its Interpretation by the Computation of Available Sites for Interaction with Solutes

1996

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Diamides, e.g., N-lauroyl-l-valine-tert-butylamide, self-associate in appropriate media through hydrogen bonding. Such selectors form with apolar solvents binary phases, for which the contribution of the polar constituent to the overall retention is the product of the retention on the pure diamide, its weight fraction (x), and a concentration dependent factor (μ x ). In this paper a model is presented to interpret the effect of the weight fraction on μ x . The diamide in the apolar solvent forms a mixture of structures of association degree 1 to n, between which n − 1 equilibria can be written. Every associate has at its terminals a site capable of hydrogen bonding to appropriate solutes (e.g., α-amino acid derivatives). It is proposed that μ x = N x /N 1, where N x is the number of available sites for hydrogen bonding at weight fraction x and N 1 is that of the pure diamide (x = 1). On the assumption that the above equilibria have closely similar constants, equations were developed to compute the number of the available sites by both numerical and analytical procedures. A good fit between the computed and experimental μ x values was found. The equations developed also permit the estimation of the minimal value of the equilibria constants as well as various other features of the diamide association−dissociation system.

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Effect of apolar diluents on the behavior of chiral stationary phases in gas chromatography. Binary mixtures of N-lauroyl-L-valine-tert-butylamide with squalane and n-tetracosane

Cited by 12 publications

References 24 publications

Selective adsorption of D‐ and L‐phenylalanine on molecularly‐imprinted polymerized organogels formed using polymerizable gelator N‐octadecyl maleamic acid

Selective adsorption of D‐ and L‐phenylalanine on molecularly‐imprinted polymerized organogels formed using polymerizable gelator N‐octadecyl maleamic acid

A new diamide‐type chiral stationary phase for chiral resolution by normal and reversed phase HPLC

Dependence on Composition of GC Retention on a Self-Associating Solvent/Hydrocarbon Mixture: Its Interpretation by the Computation of Available Sites for Interaction with Solutes

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