Effects in high-performance liquid chromatography of a high pH in the mobile phase on poly(methyloctylsiloxane) immobilized by gamma-radiation on titanium-grafted silica

Effects of high-pH environments on a stationary phase prepared by gamma-rad iation immobilization of poly(methyloctylsiloxane) on titanium-grafted sili ca were investigated by HPLC testing with standard sample mixtures. The HPL C parameters indicate good stationary phase stability to 10 000 column volu mes each of mobile phases with pH of 7, 9 and 12. At pH 13, the efficiency decreases slowly, although reasonably good separations are still possible u ntil increasing flow resistance no longer allows easy passage of the mobile phase. (C) 2000 Elsevier Science B.V. All rights reserved.