13. Can I run a gradient with my Daicel chiral column?

The use of gradients could also be envisaged to select appropriate solvent composition in terms of retention and selectivity in HPLC and SFC modes. Daicel chiral columns are perfectly compatible with them. However, as two enantiomers do not have a different polarity, it would make much sense to set the final analytical method under isocratic conditions.

When setting up a gradient screening, please keep in mind the following points:

1. The time required to re-equilibrate the column back to initial mobile phase conditions. Depending on the number of samples, it would be important to evaluate whether there are any time-savings realized from the use of a gradient.
2. It would then be important to make sure especially in HPLC-mode that the chromatographic system is able to guarantee proper/accurate metering of mobile phase composition with organic solvents, as this is not always the case with DCM, EtOAc or THF mixtures. Please note that most HPLC systems are designed to deliver good gradients in RP-mode, but they do not work properly in normal phase conditions.