Through our Supelco DEX series, we offer a broad range of GC chiral stationary phases (CSPs) with enantioselectivities that are complementary to our CHIRALDEX phases. Both lines are based on derivatized α, β or γ cyclodextrin. Supelco DEX columns use dimethyl, diacetyl and tertbutyldimethylsilyl (TBDMS) derivatives and are used to separate volatile chiral molecules, including alcohols, aldehydes, carboxylic acids, epoxides, esters and halogenated compounds. The three derivative types give ten unique GC CSPs.
Permethylated cyclodextrins - α-DEX, β-DEX, and γ-DEX 110; α-DEX, β-DEX, and γ-DEX 120
Diacetylated cyclodextrins - α-DEX, β-DEX, and γ-DEX 225
Dimethylated cyclodextrins - α-DEX, β-DEX, and γ-DEX 325
Group 2: Surface & Inclusion Interactions, Simple Derivatives...DEX 225 and 325 Group 3: Inclusion Interactions...DEX 110 and 120
DEX columns are available individually, or in convenient and economical kits. Use our Chiral Screening Service to help you choose the right column for your application.
DEX Kit I (24340): Contains one each of α-DEX 120, β-DEX 120, and γ-DEX 120. DEX Kit II (24328-U): Contains one each of β-DEX 120, β-DEX 225, β-DEX 325, and γ-DEX 225.
β-DEX 110 and 120
CD Type: β (beta) Derivative: Permethylated Phase: Non-bonded; 10% (β-DEX 110) or 20% (β-DEX 120) permethylated β-cyclodextrin in SPB-35 poly(35% diphenyl/65% dimethylsiloxane) phase Temp. Limits: 30 °C to 230 °C (isothermal or programmed)
The permethylated β-CD in β-DEX columns is unique because it contains an odd number (7) of glucose units. This asymmetrical geometry allows β-DEX columns to distinguish between the enantiomers of a large number of analytes. A β-DEX column is the first column of choice for separating any enantiomeric pair.
CD Type: α (alpha) Derivative: Permethylated Phase: Non-bonded; 20% permethylated α-cyclodextrin in SPB-35 poly(35% diphenyl/65% dimethylsiloxane) phase Temp. Limits: 30 °C to 230 °C (isothermal or programmed)
A small internal cavity in the permethylated α-cyclodextrin generates the molecule′s rigid nature and unique chiral selectivities. These columns have a high shape selectivity for positional isomers (e.g. xylenes, menthols, cresols, substituted-phenols, substituted benzenes) and epoxide enantiomers.
CD Type: γ (gamma) Derivative: Permethylated Phase: Non-bonded; 20% permethylated γ-cyclodextrin in SPB-35 poly(35% phenyl/65% dimethylsiloxane) phase Temp. Limits: 30 °C to 230 °C (isothermal or programmed)
Of the three cyclodextrins, the permethylated γ-CD in γ-DEX 120 columns has the largest cavity. This makes the γ-CD molecule more flexible and less selective in differentiating most enantiomers. Still, some large analytes (e.g., α-BHC, carvone, carboxylic acids, methamphetamine) show the greatest enantiomeric differentiation on a γ-DEX 120 column.
CD Type: α (alpha) Derivative: Diacetyl Phase: Non-bonded; 25% 2,3-di-O-acetyl-6-0-TBDMS-α-cyclodextrin embedded in SPB-20 poly(20% phenyl/80% dimethylsiloxane) Temp. Limits: 30 °C to 230 °C (isothermal or programmed)
The chiral stationary phase in α-DEX 225 columns contains 2,3-di-O-acetyl-6-0-TBDMS-α-cyclodextrin embedded in an intermediate polarity phase.
CD Type: β (beta) Derivative: Diacetyl Phase: Non-bonded; 25% 2,3-di-O-acetyl-6-0-TBDMS-β-cyclodextrin embedded in SPB-20 poly(20% phenyl/80% dimethylsiloxane) Temp. Limits: 30 °C to 230 °C (isothermal or programmed)
The chiral stationary phase in β-DEX 225 columns contains 2,3-di-O-acetyl-6-0-TBDMS-β-cyclodextrin embedded in an intermediate polarity phase. These columns provide unique selectivity for enantiomeric separations of small molecules: alcohols, aldehydes (e.g., 2-phenylpropionaldehyde), esters (e.g., methyl malate, methyl lactate), flavor compounds, and ketones.
CD Type: γ (gamma) Derivative: Diacetyl Phase: Non-bonded; 25% 2,3-di-O-acetyl-6-0-TBDMS-γ-cyclodextrin embedded in SPB-20 poly(20% phenyl/80% dimethylsiloxane) Temp. Limits: 30 °C to 230 °C (isothermal or programmed)
The chiral stationary phase in γ-DEX 225 columns contains 2,3-di-O-acetyl-6-0-TBDMS-γ-cyclodextrin embedded in an intermediate polarity phase.
CD Type: β (beta) Derivative: Dimethyl Phase: Non-bonded; 25% 2,3-di-O-methyl-6-0-TBDMS-β-cyclodextrin embedded in SPB-20 poly(20% phenyl/80% dimethylsiloxane) Temp. Limits: 30 °C to 230 °C (isothermal or programmed)
The chiral stationary phase in β-DEX 325 columns contains 2,3-di-O-methyl-6-0-TBDMS-β-cyclodextrin embedded in an intermediate polarity phase.
CD Type: γ (gamma) Derivative: Dimethyl Phase: Non-bonded; 25% 2,3-di-O-methyl-6-0-TBDMS-γ-cyclodextrin embedded in SPB-20 poly(20% phenyl/80% dimethylsiloxane) Temp. Limits: 30 °C to 230 °C (isothermal or programmed)
The chiral stationary phase in γ-DEX 325 columns contains 2,3-di-O-methyl-6-0-TBDMS-γ-cyclodextrin embedded in an intermediate polarity phase.
These kits provide the necessary columns to perform most chiral separations and run mechanistic studies, and are offered at very attractive prices. Supelco DEX Kit I is valuable for studying the effect of CD size on a separation. All three columns in the kit, α-DEX 120, β-DEX 120, and γ-DEX 120, have the same permethylated derivative, but on different size CDs. One application is to confirm enantiomer identification by monitoring elution order changes (enantioreversal) from one column to another. Supelco DEX Kit II contains four columns, each 30 m x 0.25 mm I.D., 0.25 μm, one each of β-DEX 120, β-DEX 225, γ-DEX 225, and β-DEX 325. Combining this kit with Supelco DEX Kit I spans the full range of Supelco DEX column enantioselectivity.
