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| Chiral stationary phases (CSPs) available from Daicel are based upon chiral selectors produced by derivatization of amylose or cellulose polymers. The product range available from Daicel
may be divided into two distinct groups: modern, immobilized phases and traditional, coated phases. Literature reports that 85% of chiral separations have been achieved on these CSPs which show an extremely wide range of applicability.
The key to this success is the great number of different stationary phases available to separate chiral compounds. |
Immobilized phases.The immobilized phases, namely CHIRALPAK IA™, CHIRALPAK IB™, and CHIRALPAK IC™, constitute the "Platinum Series" columns. CHIRALPAK IA and CHIRALPAK
IB are based upon the 3,5-dimethylphenylcarbamate derivatives of amylose and cellulose respectively, which are immobilized on 5-µm silica. CHIRALPAK IC has a unique chiral selector, cellulose tris 3,5-dichlorophenylcarbamate, which
brings a new separation capability to the polysaccharide phases. Preparative versions of these phases, CHIRALPAK IA, CHIRALPAK IC, and CHIRALCEL OD-I (equivalent to CHIRALPAK IB), based on 20-µm silica, are also available. The designation
of the latter phase is changed since this CSP uses an immobilization technique a little different from that used for CHIRALPAK IB. The newest additions to the Immobilized product line are CHIRALPAK IA-3, CHIRALPAK IB-3, and CHIRALPAK IC-3, 3-µm versions of immobilized IA, IB, and IC chiral phases.
These columns are intended for high-speed, high-efficiency separations of enantiomers and offer the same selectivity and stability characteristics as those of its current 5-µm immobilized counterparts. |
| Coated phases. The traditional coated chiral stationary phases (CSPs) from CHIRAL TECHNOLOGIES are now available in 3-micron particle size and offer superior speed and column resolving power. These columns packed with 3-micron CSP
offer high-speed separations, reduction in analysis time, more samples per day and a reduction in cost per sample. 3-micron columns may be used in conventional HPLC units without significant loss in performance, even with the smaller column dimensions (3-micron chromatogram and 3-micron table).
The original Daicel CSPs were formed by coating the chiral polymer from the derivatization of the amylose and cellulose on 10-micron diameter silica. Subsequently, CHIRALPAK AD, CHIRALPAK AS, CHIRALCEL OD,
CHIRALCEL OJ, CHIRALCEL OB, and CHIRALCEL OC have now been effectively superseded by products made with higher-efficiency 5-micron particles. These CSPs are designated AD-H, AS-H, OD-H,
OJ-H,
OB-H and OC-H. Because these CSPs are made by coating the polymer on the silica, any solvent that will dissolve the polymer will remove the coating and damage the CSP. For this reason there are strict
limits on the mobile phases that may be used and one of Daicel's priorities is to develop further the range of immobilized CSPs to eliminate these restrictions. |
| Structures of commercially available polysaccharide CSPs |
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