Influence of the Alcoholic Modifier on the Enantioseparation of Organophosphonate Derivatives on Cellulose tris(3,5-Dimethylphenylcarbamate) Chiral Stationary Phase Under Normal Phase Mode

Abstract

The enantiomers of fifteen O,O-dialkyl-2-benzyloxycarbonyl- aminoarylmethyl-phosphonates are directly separated on cellulose tris(3,5-dimethyl-phenylcarbamate) chiral stationary phase using different alcohols as organic mobile phase modifier. The influence of the position and properties of substituents in benzene ring, the length and steric hindrance of alkoxyl groups of the phosphonate ester on the chiral separation were discussed using different alcohol modifiers namely, ethanol, n-propyl alcohol, isopropyl alcohol, and n-butyl alcohol. The study indicates that with the use of different alcohol modifiers in mobile phase, the capacity factor (k) was in the order of k EtOH<k PrOH<k BuOH<k i-PrOH. The results also show that using n-butyl alcohol or isopropyl alcohol as mobile phase modifier achieve better chiral separation for these organophosphonate derivatives than that using ethanol or n-propyl alcohol.