NCJ Number
131533
Journal
Alcohol, Drugs and Driving Volume: 6 Issue: 2 Dated: (April-June 1990) Pages: 27-31
Date Published
1990
Length
5 pages
Annotation
In March 1989, it was announced by the Home Secretary of Great Britain that 742 drink driving convictions were to be reviewed after the Greater Manchester police admitted using n-propanol impregnated swabs when taking the blood samples.
Abstract
To date, there is still doubt in the literature regarding the degree of alcohol pick-up during venipuncture. Furthermore, the likelihood that this small amount of alcohol could be of significance when concentrations of venous blood alcohol are being used for criminal convictions for drink driving offenses remains unassessed. We analyzed the blood of 20 healthy male and female physicians in various stages of inebriation using three different methods of skin preparation, viz., dry cotton wool wipe, commercially available isopropanol (70 percent) swab, and cotton wool soaked in pure ethanol. The blood alcohol levels were then determined using headspace gas chromatography (HCG) with n-propanol as an internal standard and calibrating the machine with commercial standards. The results obtained from the subjects who had abstained from alcohol for the previous 24 hours failed to show any evidence of isopropyl alcohol (IPA) or ethanol (EtOH) having been picked up from the skin preparation. However, 3 out of the 24 samples taken from subjects who had been drinking showed a disparity between the results using a dry skin preparation and either IPA or pure ethanol, and this was directly attributable to the alcohols contained in the skin preparation. Closer analysis of these results suggests the method of needle withdrawal as the most likely cause of introduction of the skin preparation alcohol into the blood sample. It is quite possible that a small amount of n-propanol could have been incorporated into these forensic samples from the Mediswabs used during the venipuncture. However, by using the technique of relating the alcohol peak to a known internal standard peak on HGD, this would only serve to give a falsely low reading of the defendants' blood alcohol concentrations if it were to affect them at all. 1 table and 4 references (Author abstract)