Grubwieser,P.; Haidekker,A.; Pavlic,M.; Steinlechner,M.;

In this study the analytical performance of the breath alcohol analyser Alcotest MK III A from Dräger was evaluated in the concentration range of 0.25 mg/l to collect data for the determination of the blood alcohol-breath alcohol (BAC-BrAC) quotient. This breath testing device has been approved for use in Austria since 1997 and differs in some technical aspects from the Alcotest 7110 MK III Evidential, which is approved for use in Germany. In 32 controlled experiments the BAC and BrAC of 139 participants were determined simultaneously 30 min after the last consumption of alcohol. The measured BAC and BrAC values ranged between 0.14 and 1.72% (g/l), and 0.05 and 0.78 mg/l, respectively. A conversion factor (CF) between BAC and BrAC was determined from these data pairs with a minimum of 1,380 and a maximum 2,720 and a mean value of 2,062. Due to the large variability of the CF, analysis of BAC is preferable to using conversion calculations from a forensic point of view. According to our data, if only BrAC values are available a CF ranging from 1,631 (min) and 2,493 (max) can be used to convert BrAC to BAC with a statisticl significance of 95%

Rechtsmedizin 2002 12(2):104-108