Regis Technologies, Inc.
Syame Khater and Caroline West, University of Orleans rue de Chartres, UFR Sciences
A number of factors determine the success of a chiral SFC separation. The most significant one is the performance of the chiral stationary phase (CSP). Polysaccharide based CSPs are the most widely used and this study focuses on three specific polysaccharide CSPs namely RegisPack®, RegisCell®, and RegisPack® CLA-1 manufactured by Regis Technologies. The purpose of the study is to evaluate the success rate of each CSP and their complementarities.
All experiments were performed on a Jasco SFC system and an Acquity UPC2 system.
Figure 1: Success rate based on the chiral separation of 130 test racemates in SFC conditions (see text for details).
All applications were developed using 5 μm, analytical 15 cm × 4.6 mm columns.
RegisPack® and RegisCell® are coated with tris-(3,5-dimethylphenylcarbamate) of amylose and cellulose respectively. RegisPack® CLA-1 is a chlorinated polysaccharide CSP, coated with tris-(5-chloro-2-methylphenylcarbamate) of amylose.
Figure 2: A proprietary synthetic compound and sulprofos on (a) RegisCell, (b) RegisPack,and (c) RegisPack CLA-1.
One hundred and thirty chiral compounds were screened on the three different polysaccharide-type chiral stationary phases using SFC under the following operating conditions: CO2/MeOH (90:10), flow rate 3 mL/min, temperature 25 °C, outlet pressure 150 bar.
80% of the tested chiral compounds are resolved on either RegisPack®, RegisCell®, or RegisPack® CLA-1 and 30% of them are resolved on all three CSPs.
Figure 3: Viloxazine on (a) RegisCell, (b) RegisPack, and (c) RegisPack CLA-1.
RegisPack® shows the highest success rate in achieving the majority of chiral separations (64%) compared to RegisCell® (56%) and RegisPack® CLA-1 (52%). Although the complementarities between the tris-(3,5-dimethylphenylcarbamate) phases is high, RegisPack® CLA-1 is interesting considering its particular selectivity.
The chromatogram illustrates compounds that are well resolved with one CSP but have poor or no separation with the others. Depending on this finding, the complementarities of the phases could be recommended in the course of method development. Screening the three CSPs with other mobile phase compositions would undoubtedly increase the overall success rate.
Regis Technologies, Inc.
8210 Austin Ave., Morton Grove, IL 60053
tel. (847) 583-7661, fax (847) 967-1214