COMPARISON OF REVERSED-PHASE CHROMATOGRAPHIC SYSTEMS WITH PRINCIPAL COMPONENT AND CLUSTER-ANALYSIS

The separation of ethoxylated 1,1,3,3-tetramethylphenyl surfactants wa s investigated by reversed-phase liquid chromatography (RP-LC) using v arious supports (C-1, C-2, C-6, C-8, C-18, polyethylene-coated silica, and polyethylene-coated alumina) and with reversed-phase thin-layer c hromatography (RP-TLC) using impregnated silica and alumina supports. The retention data matrix was evaluated both by principal component an alysis and cluster analysis. The retention characteristics of both pol yethylene-coated supports were similar to those of C,, and the retenti on capacity of RP columns for surfactants increased with the increasin g length of the covalently bonded hydrocarbon chain. Both multivariate mathematical statistical methods gave similar results and adequate se paration was performed with the RP-LC and RP-TLC systems.