Patent ID: 6442995
Filing Date: 2002-09-03
Classification: G01N

Abstract:
An assembly for desorbing sampling tubes (20), the assembly comprising a gas chromatograph (1) known per se provided with an injector (5), the sampling tubes (20) being provided with an inflow opening (26) and an outflow opening (25), the assembly comprising an adapter (19) which is placed in the injector (5) and which is provided with a chamber (K) which is bounded by a heat conducting housing (29), placed in thermal communicating contact with a gas chromatograph oven chamber (O), the adapter (19) being arranged for placing a sampling tube (20) in the chamber (K) thereof, while in a mounted condition of a sampling tube (20) wherein it is placed in the adapter (19), the inflow opening (26) thereof is in fluid communication with a first carrier gas supply duct (41), while the outflow opening (25) of the sampling tube (20) is in fluid communication via the injector (5) with a gas chromatography column (42) disposed in the gas chromatograph (1), further comprising a valve assembly (43), a second carrier gas supply duct (44), carrier gas main supply duct (45); wherein an at least one inlet of the valve assembly (43a) is connected to the carrier gas main supply duct (45); wherein a first outlet (36) of the valve assembly (43) is connected to the first carrier gas supply duct (41); wherein a second outlet (43c) of the valve assembly (43) is connected to the second carrier gas supply duct (44); wherein the valve assembly (43) sets the carrier gas main supply duct (45) in fluid communication with either the first carrier gas supply duct (41) or the second carrier gas supply duct (44); wherein the assembly further comprises a cold trap (46), which is arranged in the oven chamber (0) of the gas chromatograph (1), as well as a first connecting duct (47) which sets the outlet of the injector (7) in fluid communication with an inlet (46a) of the cold trap (46); wherein a second connecting duct (48) sets an outlet (46b) of the cold trap (46) in fluid communication with the gas chromatography column (42); wherein a downstream end of the gas chromatography column (42) is in communication with a detector (6); wherein upstream of the cold trap (46) and downstream of the injector outlet a first T-junction (49) is provided in the first connecting duct (47), to which an outlet of the second carrier gas supply duct (44) is connected; wherein a second T-junction (50) is provided in the second connecting duct (48), to which a discharge duct (51) is connected.