High oven temperature on-column injection in capillary gas chromatography : II. Avoidance of peak distortion

Abstract High oven temperature on-column injection often produces distorted peaks, particularly when running isothermal chromatograms at the injection temperature. Peak distortion may be due to solute material pulled backwards into the cold column neck, but more often it is due to premature release of solute material from the temporarily cooled column inlet and thermal defocusing of the initial bands during this transition. The sources of peak distortion are described together with the possibilities of avoiding such problems. Summarized guidelines on how to use high oven temperature on-column injection are given.