Electrolyzer-operated gas-cylinder-free GC-FID

A new gas chromatography system, based on the use of a water electrolyzer a s its only source of gases, was designed, built, and tested. An electrolyze r-powered flame ionization detector (EFID) served as the GC detector for th e sensitive, carbon-selective detection of a broad range of volatile organi c compounds. The concept of electrolyzer-operated GC-EFID is based on the u se of the electrolyzer-produced oxygen and hydrogen gas mixture for sample desorption and sweeping in a purge-and-trap sampling system, as the analyti cal column carrier gas and as the only required EFID combustible gas mixtur e. It was found, as it has been found previously, that standard columns wit h dimethyl polysiloxane adsorption film could be operated with oxygen up to 200 degreesC, A styrene-divinylbenzene- based PoraBOND porous-layer open t ubular column was used for the GC separation, and it was found that the sys tem could be operated up to 140 degreesC with the electrolyzer-produced hyd rogen and oxygen gas mixture. Thus, the use of a water electrolyzer enabled the creation of a gas-cylinder-free GC-FID system with enhanced transporta bility and ease of use and with lower cost of operation, The gas-cylinder-f ree system operation was demonstrated with fast chromatography separation ( under 1-min total analysis time) of acetone, ethanol, benzene, toluene, and xylene with an estimated detection limit below 1 ppb. The capability of ex haled human breath analysis for industrial hygiene and medical diagnostic a pplications is demonstrated. An additional capability of total hydrocarbon content in air analysis is shown and the required minor modifications are d iscussed, (C) 2001 John Wiley & Sons, Inc.