Astec chiraldex g-ta gc column 20 m 0,25 mm

CD Type: γ (gamma)
Derivative: Trifluoroacetyl
Temp. Limits: -10 °C to 180 °C (isothermal or programmed)
Incorporates a phase consisting of a 2,6-di-O-pentyl-3-trifluoroacetyl derivative of γ-cyclodextrin.
Trifluoroacetylation of the 3 position hydroxyl groups after pentylation of the 2,6 hydroxyl groups creates a phase with high selectivity for oxygen containing analytes in the form of alcohols, ketones, acids, aldehydes, lactones, and halogenated compounds.
Features:
Separates the widest variety of enantiomers
Separates the greatest number of enantiomers
Gamma more selective than beta form
Unique retention behavior
Extraordinary versatility and chiral selectivity
Analytes:
Useful for homologous series of:
Amino acids (primary, secondary, aromatic and aliphatic)
Amines (primary, secondary, cyclic, aromatic and halogenated)
Amino alcohols
Alkanes, hydrogenated alkanes
Alcohols (aliphatic and aromatic)
Acids (halogenated and hydroxy)
Esters (aromatic, aliphatic, hydroxy, di-ester)
Diols
Lactones
Ketones
Phthalides
Sulfoxides
Mechanism Observations
Strong dipole-dipole interactions
Longer alkyl chain; greater retention; increase in enantioselectivity up to C4/C5
Halogens known to favor cavity interaction
Dipole-dipole interactions are commonly identified in the mechanism of separation for TA phases. In a homologous series of alkane enantiomers, identical alpha values are observed regardless of chain length or branching indicating only 1 or 2 carbons may be contributing to chiral recognition. Alpha values are greatly affected by size and polarity of the head group. Functional groups like epoxides, amino alcohols and alcohols can dictate the cyclodextrin selection. Aldehydes, carboxylic acids and epoxides separate better on the gamma while alcohols, alcohol amines and other linear molecules separate better on the beta derivative.
Included in GC Screening Kit 71030AST.