27 Result(s)

Article

Super/Subcritical Fluid Chromatography Separations with Four Synthetic Polymeric Chiral Stationary Phases

New synthetic polymeric chiral selectors were developed recently as chiral stationary phases. They were tested with supercritical fluid mobile phases made of CO₂ plus an alcohol modifier and 0.2% v/v trifluoroace...

X. Han, A. Berthod, C. Wang, K. Huang, D. W. Armstrong in Chromatographia (2007)

Article

HPLC Enantioseparation of 1-(α-Aminobenzyl)-2-naphthol and 2-(α-Aminobenzyl)-1-naphthol Analogs on a β-Cyclodextrin-Based Chiral Stationary Phase

The enantiomers of 1-(α-aminobenzyl)-2-naphthol and 2-(α-aminobenzyl)-1-naphthol analogs were separated isothermally on a 3,5-dimethylphenylcarbamoylated β-cyclodextrin-based chiral stationary phase (Cyclobond DM...

R. Berkecz, I. Ilisz, A. Ivanov-Sztojkov, I. Szatmári, F. Fülöp… in Chromatographia (2007)

Article

Optimization of the Synthesis of 2,6–Dinitro-4-trifluoromethylphenyl Ether Substituted Cyclodextrin Bonded Chiral Stationary Phases

The comparisons of five different chiral stationary phases (CSPs) based on 2,6-dinitro-4-trifluoromethylphenyl (DNP-TFM) ether substituted β-cyclodextrin are presented. The five CSPs differ from each other in ...

Q. Zhong, L. He, T. E. Beesley, W. S. Trahanovsky, P. Sun, C. Wang… in Chromatographia (2006)

Article

Comparison of Separation Efficiency of Macrocyclic Glycopeptide-Based Chiral Stationary Phases for the LC Enantioseparation of β-Amino Acids

Direct reversed-phase high-performance liquid chromatographic methods were developed for the separation of enantiomers of eighteen unnatural β-amino acids, including several β-3-homo-amino acids. The direct separ...

A. Sztojkov-Ivanov, L. Lázár, F. Fülöp, D. W. Armstrong, A. Péter in Chromatographia (2006)

Article

LC Enantioseparation of β-Lactam and β-Amino Acid Stereoisomers and a Comparison of Macrocyclic Glycopeptide- and β-Cyclodextrin-Based Columns

Direct reversed-phase high-performance liquid chromatographic methods were developed for the separation of the enantiomers of tricyclic β-lactams, cis-3,4-benzo-6-azabicyclo[3.2.0]heptan-7-one, cis-4,5-benzo-7-az...

R. Berkecz, R. Török, I. Ilisz, E. Forró, F. Fülöp, D. W. Armstrong… in Chromatographia (2006)

Article

LC Enantioseparation of Aryl-Substituted β-Lactams Using Variable-Temperature Conditions

Direct reversed-phase high-performance liquid chromatographic methods were developed for the separation of enantiomers of β-lactams. The enantiomers of 7 aryl-substituted β-lactams were separated on chiral statio...

R. Berkecz, I. Ilisz, E. Forró, F. Fülöp, D. W. Armstrong, A. Péter in Chromatographia (2006)

Article

LC Enantioseparation of Tryptophan Analogs on α-Cyclodextrin Stationary Phase

For the direct separation of enantiomers of tryptophan analogs, a native α-cyclodextrin-based Cyclobond III chiral stationary phase was examined. The separation conditions were optimized by variation of the diffe...

I. Ilisz, J. Sápi, D. Tourwé, D. W. Armstrong, A. Péter in Chromatographia (2006)

Article

Synthesis and Evaluation of a Synthetic Polymeric Chiral Stationary Phase for LC Based on the N, N′-[(1R,2R)-1,2-Diphenyl-1,2-Ethanediyl]bis-2-Propenamide Monomer

A synthetic polymeric chiral stationary phase for liquid chromatography based on N, N′-[(1R,2R)-1,2-diphenyl-1,2-ethanediyl]bis-2-propenamide monomer was prepared via a simple solution initiated radical polymeriz...

X. Han, L. He, Q. Zhong, T. E. Beesley, D. W. Armstrong in Chromatographia (2006)

Article

The Use of Cyclodextrin-Based LC Stationary Phases for the Separation of Chiral Dihydrobenzofuran Derivatives

The enantiomeric separation of 12 chiral dihydrobenzofurans is reported on derivatized β-cyclodextrin stationary phases using high performance liquid chromatography. The hydroxypropyl β-cyclodextrin chiral statio...

R. J. Soukup, R. V. Rozhkov, R. C. Larock, D. W. Armstrong in Chromatographia (2005)

Article

Separation of Enantiomers of Isochromene Derivatives by HPLC Using Cyclodextrin-Based Stationary Phases

Twenty chiral isochromene derivatives have been chromatographed on native and derivatized cyclodextrin stationary phases using HPLC. The most effective CSPs for the enantioresolution of these analytes in the r...

X. Han, Q. Zhong, D. Yue, N. Della Cà, R. C. Larock, D. W. Armstrong in Chromatographia (2005)

Article

High-Performance Liquid Chromatographic Separation of Stereoisomers of β-Amino Acids and a Comparison of Separation Efficiencies on Chirobiotic T and TAG Columns

Direct and indirect reversed-phase high-performance liquid chromatographic methods were developed for the separation of enantiomers of seventeen unnatural β-amino acids, including several β-3-homo amino acids....

A. Árki, D. Tourwé, M. Solymár, F. Fülöp, D. W. Armstrong, A. Péter in Chromatographia (2004)

Article

Fast Super/Subcritical Fluid Chromatography Enantiomeric Separations of Dihydrofurocoumarin Derivatives with Macrocyclic Glycopeptide Stationary Phases

Twenty-four chiral dihydrofurocoumarin derivatives and structurally related compounds were separated using super/subcritical fluid chromatography (SFC) on three macrocyclic glycopeptide chiral stationary phase...

Y. Liu, R.V. Rozhkov, R.C. Larock, T. L. **ao, D.W. Armstrong in Chromatographia (2003)

Article

Separation of β-Blockers on Chiral Stationary Phases Based on the Teicoplanin Macrocyclic Antibiotic

I. A. Anan'eva, E. N. Shapovalova, O. A. Shpigun… in Journal of Analytical Chemistry (2003)

Article

Solvent properties of the 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid

1-Butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF₆) was synthesized and purified to be used as a ionic liquid solvent. Its physicochemical properties were studied. The ionic liquid/water (P ...

S. Carda–Broch, A. Berthod, D. W. Armstrong in Analytical and Bioanalytical Chemistry (2003)

Article

Use of Unmodified and Aminated β-Cyclodextrins for the Separation of Enantiomers of Amino Acid Derivatives by High-Performance Liquid Chromatography

The separation of enantiomers of amino acid derivatives with modifiers of different structures on β-cyclodextrin and aminated β-cyclodextrin by reversed-phase high-performance liquid chromatography was studied...

I. A. Anan'eva, E. N. Shapovalova, S. A. Lopatin… in Journal of Analytical Chemistry (2002)

Article

Enantioseparation by HPLC of imino acids on macrocyclic glycopeptide stationary phases and as their (S)-N-(4-Nitrophenoxycarbonyl)phenylalanine methoxyethyl ester derivatives

The difect and indirect separation of enantiomers of secondary amino acids was studied by high-performance liquid chromatography. Direct separation was by using a macrocyclic glycopeptide, teicoplanin or risto...

A. Péter, E. Vékes, D. W. Armstrong, D. Tourwé in Chromatographia (2002)

Article

A comparison of the direct and indirect LC methods for separating enantiomers of unusual glycine and alanine amino acid analogues

Reversed-phase high-performance liquid chromatographic methods were developed for the separation of the enantiomers of five glycine and twelve alanine analogues. The enantioselective separation involved two me...

A. Péter, E. Vékes, L. Gera, J. M. Stewart, D. W. Armstrong in Chromatographia (2002)

Article

Ionic liquids as stationary phase solvents for methylated cyclodextrins in gas chromatography

Room temperature ionic liquids (RTIL) are molten salts with melting points well below room temperature. 1-butyl-3-methylimidazolium chloride is a typical example of such RTIL. It was used as a solvent to disso...

A. Berthod, L. He, D. W. Armstrong in Chromatographia (2001)

Article

Enantiomeric high-performance liquid chromatographic separation of β-substituted tryptophan analogues

The high-performance liquid chromatographic enantioresolution of β-substituted tryptophan analogues by direct and indirect methods is reported. The direct separation was carried out on chiral crown ether-bonde...

G. Török, A. Péter, E. Vékes, J. Sápi, M. Laronze, J. -Y. Laronze… in Chromatographia (2000)

Article

Comparison of Pure Nicotine- and Smokeless Tobacco Extract-Induced Toxicities and Oxidative Stress

The toxicities and oxidative stress-inducing actions of (−)-nicotine and smokeless tobacco extract (STE), containing equivalent amounts of nicotine, were studied. Toxicities were determined by colony formati...

D. Yildiz, Y.-S. Liu, N. Ercal… in Archives of Environmental Contamination an… (1999)