Chromatographie en phase gazeuse avec “backflushing” et avec programmation du gradient longitudinal positif de temperature durant l'inversion du sens du gaz vecteur

Abstract

Gas chromatography with backflushing and with programmed longitudinal positive gradient of temperature during backflushing A new method of gas chromatography with backflushing is presented. It may be defined as a two-stage operation. The first stage uses a carrier gas flow running in the usual direction while the column is isothermal. In the second stage, the gas flow is reversed and a positive longitudinal gradient of temperature is programmed at a constant rate. The more volatile solutes are thus eluted with classical chromatography, and the less volatile solutes are eluted with the backflush and the programming of temperature. The apparatus used is described and a theory of retention of solutes is set up. The advantages of our technique over classical backflushing gas chromatography are demonstrated: decreased retention times, peak skew, and a good separation of the solutes.