Reverse-Phase Liquid Chromatography of Phenol-Formaldehyde All-Ortho Oligomers

Abstract

High Performance Liquid Chromatography was proven to be a powerful method for the separation and quantitation of ortho-linked Phenol-Formaldehyde oligomers. A homologous series of oligo [(2-hydroxyl-1, 3-phenylene) methylenes] (dinuclear to octanuclear compounds) was analyzed. The samples were separated by reverse-phase chromatography and monitored at 280 nm. Optimum conditions were obtained on a μ-Bondapack C₁₈ column employing isocratic ambient elution with a metanol/water 80:20 (v/v) mixture. Four reference mixtures of oligomers of known composition were used to assure the reliability of the method. Subsequent analysis of two samples of all-ortho novolac resins was performed in order to substantiate further the validity of the technique.