Identification of heptanal and nonanal in bronchoalveolar lavage from rats exposed to low levels of ozone.

Heptanal and nonanal are identified from in vitro studies as potential biomarkers of exposure to ozone, the former resulting from ozonation of palmitoleic acid and the latter from oleic acid. An analytical method is developed based on derivatization using O-pentafluorobenzylhydroxylamine HCl and gas chromatography. These molecules also are present in the lung lavage of Sprague-Dawley rats exposed to 1.3 ppm ozone for 10 hr. These results suggest aldehydes may be useful dosimeters for ozone and indicate that unsaturated fatty acids in the lung lining fluid layer undergo ozonation in vivo.