Sensitive Photoacoustic Trace Detection of Ethylene

Tunable diode lasers have been combined with photoacoustic detection; the envisaged minimum detection limit is 20 ppb. Employing an intracavity CO2-laser set up, photoacoustic detection leads to a more than thousandfold improvement of sensitivity for C2H4. This very sensitive scheme is applied to observe the production of stress-ethylene of single plants (Rumex palustris) as response to partial inundation.