Selectivity Tuning in Chiral Dual Column Gas Chromatography

Selectivity tuning in chiral dual column gas chromatography.

The enantioselective tuning of two columns coupled in series is investigated in chiral high-resolution gas chromatography. Two columns with opposite enantioselectivities (Chirasil-L-Val and Chirasil-D-Val) are coupled in series via a T connector, and the relative retention of enantiomers chromatographed on the system is changed by varying the individual carrier gas flow rates in the coupled col...

Capillary Column Selectivity and Inertness for Sulfur Gas Analysis in Light Hydrocarbon Streams by Gas Chromatography

Enantioseparation of chiral amino acids as the N(O,S)-ethoxycarbonylated diastereomeric esters by achiral dual-capillary column gas chromatography.

The enantioseparation of 30 racemic amino acids in a single analysis is described for the determination of their absolute configurations. Two-phase extractive ethoxycarbonyl (EOC) reaction with ethyl chloroformate present in the dichloromethane phase was performed to recover amino acids from alkaline aqueous solutions. The resulting N(O,S)-EOC amino acids extracted into an organic solvent after...

Column switching analysis with packed-capillary columns in gas chromatography.

By introducing sequentially connected two packed-capillary columns, a wide range of volatile compounds were successfully separated in gas chromatography. The hyphenation of two packed-capillary columns of 1.0 mm i.d. was accomplished using a conventional 6-port valve, where the temperature of each column was individually controlled in the respective column ovens. These columns were prepared w...

Chiral ionic liquids as stationary phases in gas chromatography.

Recently, it has been found that room-temperature ionic liquids can be used as stable, unusual selectivity stationary phases. They show "dual nature" properties, in that they separate nonpolar compounds as if they are nonpolar stationary phases and separate polar compounds as if they are polar stationary phases. Extending ionic liquids to the realm of chiral separations can be done in two ways:...