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Gas Chromatography
CHIRALDEX DA
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Astec Products | Technical Resources | Chiral Services
Ordering Information: B-DA | G-DA
Astec CHIRALDEX A-DA, B-DA, and G-DA capillary GC columns incorporate a phase consisting of a 2,6-di-O-pentyl-3-methoxy derivative of either α, β- or γ-cyclodextrin. These phases are good for separations of heterocyclic amines. They have different selectivity from other phases and often show reversal in elution from the PH phases.
| Type / Name |
Derivative
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α-Phase
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β-Phase |
γ-Phase |
Max. Temp.(°C)
Isothermal |
Max. Temp.(°C)
Programmed |
| DA / Dialkyl |
2,6-di-O-pentyl-3-methoxy |
A-DA |
B-DA |
G-DA |
200 |
220 |
Features
- Hydrophobic surface
- Pronounced selectivity differences based on analyte size, shape and functionality
- Separate heterocyclic amines
- Different selectivity from other cyclodextrin derivatives
- Often shows reversal in elution order from the PH phases
- Selectivity priorities:
- A-DA - Simple epoxides, cyclic ethers, and linear substituted alkanes
- B-DA - Heterocyclic amines
- G-DA - Naphthyl analogs
Mechanism Observations
- Strongest mechanism is inclusion, therefore, size selectivity is important
- Critical temperature dependence for enantioselectivity, above this temperature no separation occurs
Size Selectivity
Unlike LC, the size selectivity and chiral recognition applies to both aromatic and nonaromatic enantiomers for these phases. Alpha substituted naphthyl structures separate well on the G-DA.
Specific Classes of Compounds Separated
Use this table as a reference to help determine the proper column based on the analyte(s) of interest.
| Type |
Compound Class |
| A-DA |
Small cyclic and aromatic amines, alcohols, and epoxides. |
| B-DA |
Heterocyclics, some multi-ring lactones, aromatic amines, sugars, certain amino acid derivatives, bicyclics, and epoxides. |
| G-DA |
Aromatic amines containing 2 or more rings, large cyclic diols, some heterocyclics, multi-ring compounds, or compounds with bulky substituents. |
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