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chiral separation on LC-MS/MS

Posted: Thu Jan 17, 2013 8:55 am
by Ruth
Dear forummembers,

I have several years expeirence using several types of reversed phase columns on LC-MS/MS.
Recently, we are asked to seperate enantiomers. I understand this is best done using a chiral stationary phase.

Do the same principles apply for reversed phase and chiral separation?
Or is it a different technique that requires more skills than those used for reversed phase separations?

Thanks for your help!

Ruth

Re: chiral separation on LC-MS/MS

Posted: Mon Jan 21, 2013 6:32 pm
by sepscientologist
Usually normal phase works the best for chiral separations. Chiraltech AD-H is one of the most commonly
used and successful. I believe Phenomenex now has a knockoff since the patent expired recently.
If you don't cringe at spraying a very flammable gas into your ESI.

Re: chiral separation on LC-MS/MS

Posted: Sat Jan 26, 2013 7:25 pm
by mbreslav
Its a different skill set. You have to test different chiral columns in the order of their known statistical success. Start with AD, then OD, etc. If you have money but not time, use automated screening with column switching valve and multiple columns. (ADH is no different with AD; just different solvent in which they ship column). Always start with polar organic (methanol, ethanol with additions of 0.1% diethylamine). There is no such thing as "normal phase or reversed phase" in chiral separations, because separation mechanism is chiral recognition, not partition or absorbance.