Analysis of aqueous samples with the multichannel silicone rubber trap and capillary gas chromatograhy

Abstract

Standard methods for the determination of semi-volatile organic air pollutants are somewhat outdated and can be improved by utilising new sample concentration techniques. Two techniques, compatible with capillary gas chromatography, were developed in this study that show promise of increased speed, cost-efficiency and ease of automation: An existing method, involving adsorption of pollutants on XAD resin, followed by liquid dichloromethane extraction, was improved by replacing the subsequent evaporative concentration step with solvent effect concentration. A technique was developed based on thick film silicone rubber traps, known to effectively accumulate pollutants from air. Novel multichannel traps, consisting of a few silicone rubber tubes positioned in parallel, were made and conditioned to give minimal degradation peaks. Breakthrough volumes were determined with the aid of permeation tube standards. As sample recovery of these traps is by thermal desorption, expensive solvents are not required. Sharp chromatographic peaks were obtained without cryogenic refocusing.