By Anonymous on Wednesday, December 10, 2003 - 01:28 am:
Can I use hepta fluorobutyric acid for LCMs ?
Upto what concentration I can used ?
By MG on Wednesday, December 10, 2003 - 06:38 am:
Yes, but only for positive ionization. The general rule for volatile buffers and additives for LC/MS, is not to exceed 10-20 mM.
For something like HFBA or TFA, you should use the smallest amount that gives adequate chromatography. It's my opinion that you should use these additives only when other options are exhausted. It will take lots of flushing to remove them from your LC system and column.
By Zelechonok on Wednesday, December 10, 2003 - 08:55 am:
Instead of using hepta fluorobutyric acid you can use column with ion-pairing reagent chemically bonded to the silica surface. Our Primesep 100 column is a reverse phase column, which retain polar basic compounds without HFBA. The mechanism of retention is similar to other RP columns with HFBA in the mobile phase. Typical mobile phase includes MeCN/water/TFA(or AmAc, HCOOH, AmFm). See multiple applications on
http://www.allsep.com/Applications_By_Column.php