The invention provides a device for extracting a vaporizable analyte from a sample gas containing the analyte and unwanted aerosol particles;the device comprising a vapour extraction chamber (2), first (3) and second (4) inlets, and first (5) and second (6) outlets;the vapour extraction chamber (2) being provided with or being linked to a heat source for heating the vapour extraction chamber (2) to a desired temperature to facilitate vaporization of analyte present in the sample gas;the first (3) and second (4) inlets being linked to an upstream end of the vapour extraction chamber (2) and the first (5) and second (6) outlets being linked to a downstream end of the extraction chamber (2);the first inlet (3) allowing a sample of gas containing the analyte and unwanted aerosol particles to be introduced into the vapour extraction chamber (2);the second inlet (4) being connected or connectable to a clean gas supply that does not contain the analyte or unwanted aerosol particles;the device being configured such that, in use, a sample gas flow (7) is established through the vapour extraction chamber between the first inlet (3) and the first outlet (5), and a clean gas flow (8) is established through the vapour extraction chamber between the second inlet (4) and the second outlet (6); whereby analyte in vapour form present in the sample gas flow (7) diffuses into the clean gas flow (8), but the clean gas flow (8) reaching the second outlet is substantially free of the said unwanted aerosol particles;the first outlet (5) serving as a waste outlet for the sample gas flow, and the second outlet (6) being connected or connectable to an instrument for analysing analyte that has diffused into the clean gas flow.展开▼
