Time course of breath acetaldehyde concentrations during intravenous infusions of ethanol in healthy men.

A gas chromatographic method was developed for the quantitative determination of acetaldehyde in expired alveolar air of human subjects. A rapid and direct gas-sampling system allow serial determinations and avoid the need for correcting for sample losses or poor recoveries. This method was evaluated in experiments with healthy men during different modes of intravenous infusion of ethanol. The time course of breath-ethanol and breath-acetaldehyde concentrations were used to estimate the coexisting blood levels. Blood acetaldehyde concentration (y) was about 2000 times less than blood ethanol (x) and the values were highly correlated r = 0.90 +/- 0.05, P less than 0.001. The regression equation was y = 2.0 + 0.303x; the intercept was significantly different from zero. Breath acetaldehyde faithfully followed the changes in breath and blood ethanol concentrations for widely varying rates of ethanol infusion.