STRUCTURE-DRIVEN RETENTION OPTIMIZATION MODEL FOR REVERSED-PHASE THIN-LAYER CHROMATOGRAPHY

The solvation parameter model is used to characterize the retention pr operties of a cyanopropylsiloxane-bonded, silica-based high-performanc e thin-layer chromatography layer with methanol-water mobile phases. D ipole-type interactions do not contribute to retention while the layer cohesion and hydrogen-bond acidity of water dominate retention for pr edominantly aqueous mobile phases, and although retention is weak for predominantly methanol mobile phases, retention is favored by lone pai r-lone pair electron interactions and diminished by hydrogen-bond type interactions in the mobile phase. The solvation parameter model is us ed to construct retention maps for the solvent optimization of the sep aration of steroids with an average difference of 0.046 R-F units betw een experimental and predicted values.