Thank you everyone who attended the live webinar: ‘Rapid method development techniques for chiral LC-MS applications‘. Below are responses to the questions posed during the live event that we did not have time to answer. We hope this is a useful resource and thank our webinar attendees and our speaker, Denise Wallworth (Sigma-Aldrich International GmbH) for her time.
1. Could I see Clenbuterol (R),(S) with this kind of column? Could I see more or less 20 pg/ml?
Clenbuterol separates well on CHIROBIOTIC V in just under 8 minutes with a resolution of 1.14. I haven’t checked the limit of quantification but would estimate it to be in the ng/mL level. For pg/mL sensitivity, it could be achievable on a sub-2 mm version of this column, and we have this in R&D currently.
2. Could you shed some light on the separation of fatty acids with cis–trans isomerism?
There are many examples of the separation of cis–trans isomers using CYCLOBOND (cyclodextrin based) chiral stationary phases (CSPs); however, as far as I know, fatty acids have not been tried and may be too linear for this type of CSP. These have not been tried on CHIROBIOTIC, but could be.
3. Can this be used with complex samples? For example if one focuses on sugars in urine?
Complex samples have been regularly and routinely separated on CHIROBIOTIC CSPs, especially as they seem to have the ability to separate closely related substances in addition to chiral ones. Sugars, however separate better on CYCLOBOND (Reference for original study: Armstrong DW, Jin HL. Evaluation of the liquid chromatographic separation of monosaccharides, disaccharides, trisaccharides, tetrasaccharides, deoxysaccharides and sugar alcohols with stable cyclodextrin bonded phase columns. J. Chromatogr. 462, 219–232 (1989).
4. The lifetime of chiral stationary phase columns has always been a concern. Do you have any comments on this?
I think that in the early days of CSPs this was true, but as long as usage and storage protocols are followed, a lifetime as good as a routine reversed phase column can be achieved for most CSPs. In the case of CHIROBIOTIC, the lifetime seems to be better than most, perhaps a combination of multi-covalent bonding chemistry used to bind the selector to the silica, and the effectiveness of a regeneration procedure that can be followed. They have been used effectively and extensively for bioanalytical applications, even with a simple protein precipitation sample preperation method. Ideally, of course, use all CSPs after an effective SPE method in bioanalytical methods.
The webinar is available here – Rapid method development techniques for chiral LC-MS applications.