AN IMPROVED THERMAL MODULATOR

A thermal modulator for gas chromatography includes an analytical capillary to be traversed by analytes and that is interposed between two gas chromatographic columns; a cooling system having a cold zone, a support element associated with the cold zone and supporting a portion of the analytical capillary at a corresponding or slightly higher temperature than the cold zone, so as to define a trapping portion of the analytes; a control system, which selectively controls the emission of pulsed current to electrically conductive elements associated with the analytical capillary to heat the trapping portion and cause the release or desorption of previously immobilized analytes; and a heating system of a portion of the analytical capillary, positioned outside of the support element and upstream of the support element, so as to generate a rapid expansion of the gas contained in the portion and facilitate the advancement of the released or desorbed analytes.