Study of Chromatographic Retention in Phosphate Solution on the Basis of Linear Solvation Energy Relationships

Abstract

Two kinds of phosphates i.e., sodium dihydrogen phosphate (NaH₂PO₄) and disodium hydrogen phosphate (Na₂HPO₄) were used as additives in linear solvation energy relationships (LSER) model to investigate the fundamental chemical interactions governing the retentions of 7 aromatic compounds. The effects of different concentrations of the buffer and modifier on the retentions were discussed by using acetonitrile/water (v/v) mobile phases on a C₁₈ column. Linear solvation energy relationships model demonstrated high potential to predict retention factors with very high correlation coefficients (r² > 0.99 in NaH₂PO₄ and r² > 0.96 in Na₂HPO₄). A comparison of predicted and experimental retention factors suggests that LSER formalism is able to reproduce the experimental retention factors of the solutes studied in the different experimental conditions adequately.