By bkalvakota on Wednesday, October 4, 2000 - 10:07 am:
I am working on method development to separate the degradation products of a formamide. The best method that can separate the degradants involves: Symmetry C8 column, 35C, 1 ml/min, 280nm, and the mobile phase consists of 20-25% acetonitrile and 75-80% TFA solution with 10mM sodium hexane sulfonate (ion pairing agent).
So, the problem is when I collect my fractions for subsequent analysis on Mass Spec, it is the interfernce from Sodium hexane sulfonate. Leading to my question, as to how I can sequester the ion pairing agent from my collected on LC.
I would really appreciate any comments or suggestions. Thanks in advance!
By Jim Wheatley on Friday, October 6, 2000 - 05:19 am:
You may be able to desalinate your product by loading the solution onto a semi-prep or prep C18 column, either a commercial one or one you prepare from bulk packing, like a large-scale solid phase extraction. Elute with water after loading until the sodium salt has passed (observed at 218nm), then with 100% ACN to elute your compound. I assume you have eliminated liquid-liquid extraction methods.
By Anonymous on Friday, October 6, 2000 - 11:16 am:
hoe about zip-tips from milli-pore ?
By Jim Powers on Friday, December 29, 2000 - 10:10 am:
Try using Nonylfluoropentanoic acid as a volatile ion-pair reagent.
By Anonymous on Friday, February 2, 2001 - 01:03 pm:
You might try rotovapping your fractions to dryness, then reconstitute them in 100% MeCN or MeOH. This should effectively precipitate the salts.
By Anonymous on Wednesday, April 18, 2001 - 10:02 am:
Hi, Jim,
Do you have any references on using Nonylfluoropentanoic acid as a volatile ion-pair reagent? Thanks.
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