Purification of OV‐17 by supercritical fluid fractionation for fused silica capillary gas chromatography

Abstract

Commercially available OV-17 was partitioned into a low and a higher molecular weight fraction by supercritical fluid extraction with carbon dioxide. This higher molecular weight fraction is more thermally stable than the original OV-17 due to its more viscous and gum-like nature. Based on the growing evidence in the literature that a deactivating agent for fused silica open tubular columns should be compatible with the stationary phase, a precoat of 1,3,5-trimethyl-1,3,5-triphenylcyclotrisiloxane was applied prior to the static coating of high molecular weight OV-17. Fused silica OV-17 columns prepared in this fashion are stable up to 300%.

Removal of Organic Impurities from Polymer Pellets

“…An U.S. Patent has described the removal of cyclic oligomers from polyoxyalkylene using supercritical propylene [2]. Barry [3] discussed the upgrading of a silicone polymer, designated OV-17, which is used in gas chromatography as a stationary phase. An interesting study on the extraction of oligomers from polyamide using methanol has been presented by Sridhar and Hartig [4].…”