Gas chromatographic determination of vapor-phase biomarkers formed from rats dosed with CCl4

Sprague-Dawley rats dosed with CCl4 (3 ml kg-1) were placed in a glass chamber through which air was passed continuously at a rate of 60 ml min-1. Volatile aldehydes and ketones in expired air from rats were derivatized to thiazolidines by passing the effluent gas stream through an aqueous cysteamine solution. The thiazolidine derivatives were then extracted and analyzed by gas chromatography with a nitrogen-phosphorus detector and gas chromatography/mass spectrometry. The compounds identified were formaldehyde, acetaldehyde, acetone and formyl chloride. There were no appreciable differences in levels of formaldehyde and acetaldehyde between CCl4-dosed rats and control rats, whereas the levels of acetone in CCl4-dosed rats showed an increase compared to those in control rats. Results suggest that acetone is the major volatile carbonyl compound produced following acute doses of CCl4. Results of thiobarbituric acid assay on the livers from a control rat and a CCl4-dosed rat did not show any appreciable differences.