Effect of mobile phase acidic additives on enantioselectivity for phenylalanine analogs

The use of acidic mobile phase additives allows the chiral separation of un derivatized phenylalanine analogs on a common amylosic column. In addition to decreasing retention and band-broadening arising from non-ideal interact ions, acidic additives may also increase selectivity. This appears to be du e to the minimization of non-selective binding in the recognition site. Eff ects of the additives are related to additive pK(a) and size. Ethanesulfoni c acid was typically the most effective additive with trifluoroacetic acid being one of the least effective. (C) DuPont Pharmaceutical Company. Publis hed by Elsevier Science B.V. All rights reserved.