AN IMPROVED THERMAL MODULATOR

Improved thermal modulator (2) for gas chromatography comprising: an analytical capillary (4) to be passed through by analytes and intended to be interposed between two gas chromatographic columns (1,3), a cooling system (8) comprising a cold zone (10), a support element (11) associated with said cold zone (10) and configured to support a portion (17) of said analytical capillary (4) so that saidportion (17) is at a substantially corresponding or slightly higher temperature, with respect to that of said cold zone (10), said portion (17) of said analytical capillary (4) which passes through and/or is in contact with said support element (11) thus defining the trapping portion (17) in which the analytes passing through said capillary (4) are intended to be trapped/immobilized, control means (14) which selectively control the sending of pulsed current to electrically conductive elements (70, 71) associated with said analytical capillary (4) so as to heat said trapping portion (17), thuscausing the release/desorp