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 tr ace levels of hydrogen sulfide and carbon oxysulfide in the oil-from-c oal industry. In order to improve an existing method based on a polyme r bed concentrator, a porous layer open tubular column, and a flame ph otometric detector, time-optimization of the various steps involved wa s attempted, Use of a redesigned concentrator, changed column operatin g conditions, and a photoionization detector reduced analysis times fr om 6.5 to 3 min and cycle times from 8 to 3 min. This could be achieve d without compromising the 10 ppb detection limit required.