An automated fluorometric procedure for the enzymatic determination of ethanol in fingertip blood.

An automated fluorometric procedure, using AutoAnalyzer modules and based on the alcohol dehydrogenase reaction, has been developed for the determination of ethanol in fingertip capillary blood samples. Whole blood is measured directly from the finger prick into 0.02-mi. capacity automatic-filling disposable micropipets. The sample is quickly discharged into an AutoAnalyzer cup containing 1.0 ml. of water. This dilution can be placed on the sampler plate for immediate analysis or preserved under refrigeration for future use. The time required for sample flow from sampler to fluorometer cuvet (and recording of results) is 16 mm. The coefficient of variation of replicate analyses is approximately 1%. Analyses of blood to which varying amounts of ethanol was added gave a mean recovery of 101%. As described, the method is designed to extend over the ethanol concentration range of 10-300 mg./100 ml. of whole blood. Analysis of undiluted blood or of weaker dilutions of blood samples would permit the accurate determination of as little ethanol in whole blood as 0.2 mg./100 ml. or as much as 600 mg./100 ml.