Laser photoacoustic spectroscopy: A powerful tool for measurement of trace gases of biological interest at sub-ppb level

A high sensitive photoacoustic system has been developed to monitor trace gases released by biological samples at concentrations of sub-ppb level. We have applied this technique to measure the release of the plant hormone ethylene during seed germination and ripening of climacteric fruits and of the marker ethylene as a result of doping cultures of human cells with heavy metals, of damaging living organisms by ionising radiation(X-ray)and of unleashing lipid peroxidation in lung epithelium following the inhalation of cigarette smoke.