Detection of trace gases from long term stored fruit and respiration of insects

Sensitive photoacoustic detection in combination with an infrared cw CO laser has been used as a analytical tool to monitor trace gases emitted from biological tissue. The CO laser radiates at some 300 laser lines covering the spectral region between 1280 and 2050 cm^-1. Biologically interesting gases can be detected simultaneously by choosing a set of laser lines corresponding to the fingerprint re-vibrational absorption patterns of these gases in this laser wavelength region. The detection sensitivity has been improved by inserting the photoacoustic cell in the laser cavity. The intracavity laser power amounts up to 40 W at the strongest lines; ideally suited to monitor low levels of trace gas emissions using photoacoustic detection