Daicel expanded its extensive portfolio of immobilized columns to include CHIRALPAK® ZWIX(+) and CHIRALPAK ZWIX(-), two columns packed with novel zwitterionic chiral stationary phases(CSPs). The CHIRALPAK ZWIX columns were developed for separation of a great variety of zwitterionic molecules, specifically, for separation of underivatized amino acids, although customers are reporting many successful separations on other difficult-to-separate analytes as well.
ZWIX selectors are zwitterionic molecules that incorporate both anion- and cation-exchange functional groups. These novel ZWIX selectors exhibit exceptional enantioseparation capabilities toward zwitterionic molecules such as amino acids and small peptides.
To learn more about the ZWIX selectors, columns and their applications, click here.
Anion Exchange Columns
CHIRALPAK QN-AX and CHIRALPAK QD-AX are enantioselective weak anion-exchange (AX) HPLC columns. The chiral selectors for CHIRALPAK QD-AX and CHIRALPAK QN-AX anion exchange phases are based on complementary quinine (QN) and quinidine (QD) derivative selectors bonded to high-efficiency 5-µm diameter spherical silica. The structure of these selectors is such that a tertiary amine is located in a three-dimensional cleft surrounded by additional hydrogen binding sites and a large aromatic group. This combination provides excellent separations of chiral acids. These columns can be used in reversed-phase (RP) mode or in polar organic mode (non-aqueous, polar organic solvents containing organic acids and bases as buffer constituents). In addition, the separation of chiral basic and neutral compounds may also be possible, but usually under normal-phase (NP) conditions.
To learn more about the QN-AX and QD-AX selectors, columns and their applications, click here.
Columns packed with the CHIRALPAK QD-AX and CHIRALPAK QN-AX selectors are available in 2.1-, 4.6- and 20-mm internal diameter to allow separations on analytical and semi-preparative scales.
Crown Ether Columns
CROWNPAK® CR(+) & CR(-) contain a chiral crown ether as a chiral selector, which is coated onto a 5-µm silica support. CROWNPAK selectors are mainly used to separate chiral amino acids and other small molecules with primary amine groups. The elution order of the enantiomers can be reversed when necessary.
Acidic mobile phases such as perchloric acid (pH 1 to 2), are used to operate these columns under standard conditions. To shorten the retention time of hydrophobic samples, the addition of methanol (15% maximum v/v) has been shown to be effective for CROWNPAK CR(+) & CR(-).
CROWNPAK CR-I(+) & CR-I(-) columns and stationary phases are the newest addition to this family of chiral selectors. The crown ether selectors are immobilized on 5-µm silica support. Immobilization extends the range of solvents used for mobile phases such as acetonitrile and ethanol, thereby enhancing enantioselective resolution of chiral compounds. Use of the immobilized CROWNPAK CR-I(+) & CR-I(-) selectors also provides longer column life time.
Ligand Exchange Columns
CHIRALPAK WH & MA(+) contain amino acids and their derivatives as chiral selectors. These columns are ligand-exchange type columns and employed with an aqueous solution of copper sulfate (0.1 to 2mM). The columns can tolerate use of organic modifiers such as methanol and acetonitrile to affect the separation.
Chiral Technologies provides detailed Instruction Manuals containing column descriptions, operating conditions and guidelines for method development. Exercising good column care is important for column performance.