RAPID METHOD FOR BLOOD ALCOHOL DETERMINATION BY HEADSPACE ANALYSIS USING AN ELECTROCHEMICAL DETECTOR

• NCJ Number: 47272
• Journal: Journal of Forensic Sciences Volume: 23 Issue: 2 Dated: (APRIL 1978) Pages: 283-291
• Author(s): A W JONES
• Date Published: 1978
• Length: 9 pages
• Corporate Author: American Soc for Testing and Materials
• Sale Source: Karolinska Institutet
• Publication Format: Article
• Language: English
• Country: United States of America

Annotation

THE ALCOLMETER EVIDENTIAL DEVICE (AED), A BREATH-TESTING INSTRUMENT THAT ASPIRATES A SAMPLE OF BREATH OR VAPOR INTO AN ELECTROCHEMICAL CELL FOR QUANTITATIVE ETHANOL OXIDATION CAN BE USED FOR BLOOD ALCOHOL ANALYSIS.

Abstract

THE ASPIRATING PROPERTY OF THE SAMPLING VALVE USED IN THE AED ALLOWS FOR THE USE OF THE DEVICE FOR HEADSPACE ANALYSIS BY FITTING THE SAMPLING HEAD WITH A NOZZLE CONNECTION TO HOLD A LUER-FITTING HYPODERMIC NEEDLE IN PLACE OF THE MOUTH PIECE NORMALLY USED FOR BREATH ALCOHOL ANALYSIS. THE BLOOD SAMPLE TO BE ANALYZED IS CONTAINED IN A 10 ML SERUM BOTTLE. THE TECHNIQUE MAKES USE OF THE QUOTIENT BETWEEN AIR/BLOOD AND AIR/WATER PARTITION RATIOS WHICH DEFINES THE ETHANOL EQUILIBRIUM BETWEEN THE BLOOD SAMPLES AND THE AQUEOUS STANDARDS. THE ETHANOL PARTITION TO THE VAPOR IS VERY LOW AT ROOM TEMPERATURE, WHICH MEANS THAT THE EQUILIBRIUM VAPOR PHASE MAY BE SAMPLED WITHOUT MATERIALLY AFFECTING THE AQUEOUS CONCENTRATION, AND THE EXACT VOLUME OF THE BLOOD SAMPLE ANALYZED NEED NOT BE KNOWN. A DETERMINATION CAN BE MADE WITHIN 2 MINUTES AND ONLY 0.1 ML BLOOD IS REQUIRED FOR EACH ANALYSIS. THE DETECTOR RESPONSE WAS LINEARLY RELATED TO ETHANOL CONCENTRATIONS UP TO 3.0 MG/ML, AND THE DETECTOR APPEARS TO BE HIGHLY SPECIFIC FOR ETHYL ALCOHOL WITH SEVERAL HUNDRED ALCOHOL-FREE SAMPLES BEING CORRECTLY ANALYZED. THE STANDARD DEVIATION IS LESS COSTLY THAN THE SCOTTISH METHOD. THE MOTIVATION ACCURACY OF THE METHOD BASED ON COMPARISON WITH AN AUTOMATED ALCOHOL DEHYDROGENASE TECHNIQUE WAS HIGH, THE MEAN RECOVERY BEING 102.2 PERCENT OF THE ATTRIBUTED CONCENTRATION. THIS METHOD COMPARES FAVORABLY WITH CONVENTIONAL BLOOD ANALYSIS TECHNIQUES USED IN FORENSIC AND TOXICOLOGY LABORATORIES. THE SIMPLICITY AND RAPIDITY OF THE METHOD MAKE IT IDEAL FOR SERIAL DETERMINATIONS, AS IN MASS SCREENINGS OF BIOLOGICAL MATERIALS FOR THE PRESENCE OF ETHYL ALCOHOL. REFERENCES ARE PROVIDED. (JAP)