Device for coupling a microchromatograph with a mass spectrometer and analyzing device

The invention concerns a coupling device connecting a micro-chromatograph ( mu CG) output to a mass spectrometer input, said device comprising a capillary tube whereof one end is sealingly connected to the mass spectrometer vacuum source via an interface device, and whereof the other end is loosely connected to the micro-chromatograph output open to the atmosphere; the length and the diameter of the capillary tube being selected so that the flow rate inside the capillary tube is very close to the flow rate at the micro-chromatograph output; the interface device being further provided with heating means for adjusting very accurately the flow rate tapped by the capillary tube.