EVALUATION OF REVERSED-PHASE COLUMNS FOR THE ANALYSIS OF DIPHENYLMETHANE DERIVATIVES

Four reversed phases were tested in RPLC of newly synthesized diphenyl methane derivatives. Non-deactivated Kromasil C-8 and Beckman C-18 and deactivated Supelco LC-8-DB and Supelco LC-IX-DB reversed phases were evaluated. Column supplier, deactivation and the presence of amine mo difier (triethylamine, TEA) were used as variables and capacity factor s (k) and asymmetry factors (As) were measured. Two different mobile p hase systems were used: Acetonitrile: ammonium acetate (0.1 M) and met hanol: potassium dihydrogen phosphate (0.02 M). According to the resul ts of this comparative study, non-deactivated Kromasil C-8 and Beckman C-18 were found to be the most suitable phases for our applications e .g., synthesis purity and lipophilicity studies concerning antihistami ne-like compounds. For most of the compounds involved in this study, t he use of these phases requires TEA as an amine modifier. Addition of the amine also made it possible to use the deactivated phases, e.g., S upelco C-8 and C-18 columns. The RPLC method was used to evaluate the lipophilicity of some DPPE derivatives, compared to known antihistamin ergics.