Citation

Romhild W, Bartels H, Wittig H, Schmidt U, Krause D, Jachau K. Blutalkohol 2001; 38(4): 223-232.

Affiliation

Institut fur Rechtsmedizin, 39120 Magdeburg, Germany

Copyright

(Copyright © 2001, International Committee on Alcohol, Drugs and Traffic Safety and Bund gegen Alkohol und Drogen im Straßenverkehr, Publisher Steintor Verlag)

DOI

unavailable

PMID

unavailable

Abstract

Comments on an expert report issued in 1992 by the Bundesgesundheitsamt (public health department) [1] on the reliable evidence value of breath alcohol concentration were based on the assumption that Henry's law would apply to the thermodynamic equilibrium between the alveolar blood ethanol concentration and the alveolar air ethanol concentration. Conducting experiments in a sealed system at 37 (degrees)C using an HS 40-GC-FID system and an HS 800-GC-MS system proved this assumption. The thermodynamic equilibrium between the blood homogenates containing ethanol (blood alcohol concentration of 0.2 (per mille) to 2.99 (per mille)) and the vapour chamber of the headspace tube did not occur until after about 10 minutes. After 10 to 20 seconds only half and after 1 to 2 minutes three quarters to four fifths of saturation was reached. Therefore, in contrast to the author's assumption given in the above public health department report (BGA) [1], it is not to be expected that the thermodynamic equilibrium between the alveolar blood ethanol concentration and the alveolar air ethanol concentration occurs within a period of a few seconds up to approximately one minute only, i.e. from the time of inhaling and exhaling against the resistance of the breathalyser Alcotest 7110 up to the time when the result of the breath air measurement is obtained. The path of the saturation curve rising steeply in the beginning is the main factor suggesting that the way in which a person breathes must have a stronger influence on breath air alcohol than assumed to date. Preliminary investigations revealed deviations of up to approximately (plus or minus) 0.05 mg/l [14]. The results of several series of investigations on this issue will be discussed in another publication.