RETENTION CHARACTERISTICS OF TITANIUM-DIOXIDE AND POLYETHYLENE-COATEDTITANIUM-DIOXIDE AS REVERSED-PHASE SUPPORTS

The retention of 19 solutes markedly differing in their physicochemica l characteristics was determined on titanium dioxide and polyethylene- coated titanium dioxide columns in water and water-methanol eluent mix tures. Principal component analysis was used for the elucidation of th e relationship between retention behavior and physicochemical paramete rs. Polyethylene-coated titanium dioxide showed stronger retention tha n titanium dioxide did, proving the retention increasing effect of pol yethylene coating. Retention parameters formed a loose cluster with th e excess molar refraction and the effective hydrogen bond acidity of s olutes on the two-dimensional nonlinear map of principal component loa dings, indicating the involvement of steric conditions and electronic interactions in the retention.