High speed analysis of H2S and COS impurities in coal gas by capillary gas chromatography

There is a need for rapid, on-line, gas chromatographic analysis of trace levels of hydrogen sulfide and carbon oxysulfide in the oil-from-coal industry. In order to improve an existing method based on a polymer bed concentrator, a porous layer open tubular column, and a flame photometric detector, time-optimization of the various steps involved was attempted, Use of a redesigned concentrator, changed column operating conditions, and a photoionization detector reduced analysis times from 6.5 to 3 min and cycle times from 8 to 3 min. This could be achieved without compromising the 10 ppb detection limit required.