Applications of ammonium trifluoroacetate as an additive for elution of chiral acids and bases from derivatized polysaccharide stationary phases

The ability ammonium trifluoroacetate as an additive for elution of acids and bases from derivatized polysaccharide chiral stationary phases was first observed in the process of developing normal-phase chiral HPLC methods in our lead-generation programs. To demonstrate this ability on a broader scale, chiral HPLC methods containing this additive in the mobile phases were developed to resolve selected acidic, basic, and neutral racemates, which are considered standards in the pharmaceutical industry and for which published methods exist. The mobile phases of these published methods contain acidic and/or basic additives (e.g., trifluoroacetic acid or diethylamine). This article demonstrates the versatility of ammonium trifluoroacetate additive in resolving the enantiomers of acidic and basic racemates on the same derivatized polysaccharide chiral columns. This resolution is achieved without changing the mobile phase between the analysis of acidic and basic racemates and also without observation of stationary-phase "memory effect." This chiral method development strategy can result in significant savings of cost and time.