Astec Chiraldex® GC Capillary Columns

 

• Resolve aromatic and nonaromatic enantiomers
• Pure cyclodextrin derivative coating
• No racemization of chiral stationary phase at elevated temperatures

 

Chiraldex® capillaries are based on derivatized cyclodextrins, which are chiral in nature formed by the α-1,4 linkage of glucose units into toroidal shaped structures. The enzyme cyclodextrin glucosyl transferance (CGT) cleaves partially digested starch and links the glucose units into predominantly three forms, referred to as alpha, beta, and gamma; 6, 7, and 8 glucose units, respectively. These cyclodextrins are thermally stable, highly crystalline and virtually insoluble in most organic solvents. Using the three forms of cyclodextrin, Astec has manufactured derivatives that exhibit properties allowing them to be used as GC phases. They are:

– Permethylated Hydroxypropyl (PH)
– Dialkylated (DA)
– Trifluoroacetylated (TA)
– Propionylated (PN)
– Butyrylated (BP)
– Permethylated (PM)
– Dimethylated (DM)

 

The prefix A, B, G describes the cyclodextrins alpha, beta, and gamma, respectively. The suffix describes the nature of the derivatization i.e., G-TA refers to Gamma Trifluororacetylated phase. The most striking characteristic of these phases is that they separate nonaromatic enantiomers including saturated alcohols, amines, carboxylic acids, epoxides, diols, polyols, cyclic, bicyclic, heterocyclic compounds, lactones, amino alcohols, amino acids, halohydrocarbons, α-halocarboxylic esters, pyrans, and furans. Little functionality is required for chiral recognition (Table 1). Also, there can be reversals of elution order from one series to the next as well as from one cavity size (beta) to another (gamma). The acylating reagent also can contribute to stereo-selectivity.

 

Astec Chiraldex® GC Capillary Columns

Phase
Length
i.d.
Film
Temp. Limits*
Part Number
B-PM
30m
0.25mm
0.125μm
230/250°C
4711
A-TA
30m
0.25mm
0.125μm
180/180°C
4127
B-TA
30m
0.25mm
0.125μm
180/180°C
4133
G-TA
20m
0.25mm
0.125μm
180/180°C
4137
30m
0.25mm
0.125μm
180/180°C
4139
50m
0.25mm
0.125μm
180/180°C
4639
B-PH
30m
0.25mm
0.125μm
200/220°C
4094
B-DA
20m
0.25mm
0.125μm
200/220°C
4113
G-PN
30m
0.25mm
0.125μm
200/220°C
4668
G-BP
30m
0.25mm
0.125μm
200/220°C
4670
B-DM
30m
0.25mm
0.125μm
230/250°C
4727

 

 

General Classes of Compounds Separated on Chiraldex™ Capillary Columns
Chiraldex® B-PH:
Most structural types of compounds including linear and cyclic amines and alcohols, carboxylic acids, lactones, amino alcohols, sugars,
bicyclics, epoxides, haloalkanes, and more
Chiraldex® B-DA:
Nitrogen heterocyclics, heterocyclics, some bicyclics, and epoxides, lactones, aromatic amines, sugars, amino acid derivatives
Chiraldex® A-TA:
Smaller alcohols, amino alcohols, amino alkanes, and diols
Chiraldex® B-TA:
Broad range alkyl alcohols, halo acid esters, amino alkanes, halocycloalkanes, certain lactones, diols, alkyl halides, furan and pyran
derivatives
Chiraldex® G-TA:
>350 pairs chiral alcohols, diols, polyols, hydrocarbons, lactones, amine alcohols, halocarboxylic acid esters, homologous series, furan
and pyran derivatives, epoxides, glycidyl analogs, and haloepihydrins
Chiraldex® G-PN:
Epoxides, higher alcohols >C4, lactones
Chiraldex® G-BP:
Amino acids, certain primary amines and furans
Chiraldex® B-PM:
Acids, alcohols, barbitals, diols, epoxides, esters, hydrocarbons, ketones, lactones, and terpenes
Chiraldex® B-DM:
Selectivity similar to PM and PH, but with shorter retention times, and greater resolution. Especially applicable to aliphatic, olefenic, and
aromatic enantiomers