Direct headspace sampling with on-column thermal focusing in capillary gas chromatography

Abstract

A simple and inexpensive home-made device for thermally focusing the chromatographic band in a short length of the capillary column itself is described. The system allows one to optimize the direction and the effect of the thermal gradients established during the cryofocusing and thermal focusing and also provides an effective and rapid desorption of the sample. As a result, a simultaneous double thermal focusing effect, which improves the chromatographic resolution of the less retained solutes, is achieved. Examples of headspace analysis performed with the proposed device are included.