Stability of the RegisPack® Chiral Stationary Phase Under Reversed-Phase LC Conditions

Ted Szczerba, Regis Technologies, Inc.

An investigative study was carried out to assess the feasibility and stability of employing a RegisPack® column under reversed-phase conditions.

A random selection of five compounds was chosen for this study. The compounds include Troger's Base, Flavanone, Chlormezanone, Omeprazole, and Trans-stilbene oxide (TSO).

A 10 μ, 25 cm × 4.6 mm RegisPack® column was used for the study.

Table I

The compounds were tested on a fresh column and then at intervals after treatment of 1,000 mL, 3,000 mL, 5,000 mL, and 10,000 mL of a mobile phase consisting of H₂O/CH₃OH (60/40).

Figure 1

All compounds were tested at a flow rate of 1.5 mL/min consisting of a mobile phase made up of CH₃OH/H₂O (95/5) (except Omeprazole). Omeprazole utilized a mobile phase consisting of 100% methanol. Capacity factors and separation factors were measured after each interval. Following are the summarized results of this study.

Figure 2

Conclusion

The data shows that the RegisPack® CSP can tolerate the use of up to 60% water in the mobile phase for prolonged periods with no significant deterioration of the CSP.

Note: Running the RegisPack® column under reversed-phase conditions does alter the characteristics of the column. Methods that were previously run under normal-phase conditions may be altered. If the column is used under mobile phase conditions containing water, it should be dedicated to RP conditions and not be used under NP conditions.

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