New instrument using gas sensors for the quantitative analysis of ethanol in biological liquids

A gas sensor was built into an instrument to measure ethanol in biological liquids by determining head space ethanol concentrations without chromatography. The analysis of plasma, urine, and whole blood containing ethanol over the range 20-640 mg/dl determined by this novel instrument is fast (30 sec), accurate (r = 0.99), and precise (coefficients of variation 0.6-1.8%) when compared with gas chromatography. The addition of alcohol dehydrogenase, beta-nicotinamide adenine dinucleotide, and semicarbazide to samples allows ethanol to be distinguished from other alcohols. The instrument can be built and operated at modest costs thus allowing its use in multiple settings.