Partition ratio of acetaldehyde between blood and breath after ethanol consumption.

Breath samples which were collected into Alcomille Breath Bags (Etzlinger Electronics, Geneve, Switzerland) were assessed for their acetaldehyde and ethanol levels by gas chromatography. Simultaneously, their levels in the venous blood were determined with the PCA method. A good correlation fit for acetaldehyde and ethanol levels was obtained in both blood and breath samples, respectively. The blood/breath partition ratio for acetaldehyde was 109 +/- 10 and that for ethanol was 2,300 +/- 100. The water/air, saline/air, and plasma/air partition ratios of acetaldehyde in vitro were 119, 120, and 155, respectively. Conversely, the water/air, saline/air, plasma/air, and blood/air partition ratios of ethanol were 2,160, 2,040, 1,920 and 1,720, respectively. The acetaldehyde in the bag was well preserved. In analyzing breath acetaldehyde, it is very important that only the end expiratory air is collected. Determination of acetaldehyde level with Alcomille Breath Bag is very useful to investigate alcohol metabolism, when some problems exist in the collection of blood samples and in the treatment for the analysis of blood acetaldehyde.