Disclosed is a method for collecting different selected exhaled breath samples, or fractions thereof, on a single sample capture device, the method comprising the steps of: (a)collecting a first exhaled breath sample by contacting the sample with a capture device comprising an adsorbent material； (b)collecting a second exhaled breath sample by contacting the second sample with said capture device, wherein the first and second exhaled breath samples are caused to be captured on the capture device in a spatially separated manner.
