3. What solvents can I use with CHIRALPAK® immobilised columns? Are there any solvents that I should not use with the immobilised columns?
There are currently no known organic solvents which will damage the CHIRALPAK immobilised columns in any way.
Extensive testing has been carried out with many common organic solvents, including hexane or heptane/alcohols, methanol, isopropanol, ethanol, acetonitrile, dichloromethane, chloroform, tetrahydrofuran, ethyl acetate, acetone, methyl acetate, MTBE, dimethylformamide, dimethylacetamide, etc.
See question 7 for the most useful solvent mixtures to be used as mobile phases.
Where the columns have been extensively used and have perhaps become fouled with impurities or non-eluted compounds they can readily be cleaned by flushing with dimethylformamide, THF, or ethyl acetate. Regeneration protocols are detailed in the instruction manuals.
When used in reversed-phase chromatography, the columns should not be operated below pH 2 or above pH 7. The upper range only can be extended to pH 9, provided that a suitable buffer is employed, and that a guard cartridge is used and is changed at least once every 200 injections at this pH.