Gas chromatograph

A device for characterizing a gas, said device comprising:

• a gas chromatograph column comprising a conduit containing one or more regions of a first adsorbent material distributed along its length;
• a first MOS gas sensor at a proximal extremity of said conduit situated so as to detect at least a first molecule in said conduit;
• a second MOS gas sensor at a distal extremity of said conduit situated so as to detect at least a second molecule in said conduit;
• at least one said region of said first adsorbent material being situated between said first MOS gas sensor and said second MOS gas sensor;
• and
• an inlet for introduction of said gas at said proximal extremity of said conduit, wherein said conduit, said first MOS gas sensor and said second MOS gas sensor are so disposed that a gas sample being introduced at said inlet proceeds through said first MOS gas sensor, said conduit and said second MOS gas sensor in sequence, and wherein
• said device being adapted to record the output of said first MOS gas sensor and said second MOS gas sensor as said gas diffuses along said conduit to compile a fingerprint of said gas, and to obtain an identification of said gas based on a comparison of said fingerprint to a library of reference fingerprints corresponding to known gases, where said gas is identified as the known gas whose reference fingerprint matches said reference fingerprint most closely.