The determination of ethanol in whole blood by differential pH measurements

EtOH [64-17-5] was estd. in human blood by the detn. of the difference in pH between blood samples without and with alc. dehydrogenase + aldehyde dehydrogenase. Relative std. deviation was <1.54% in the range of 10-40 mmol EtOH/L. Results were comparable with those obtained by head-space gas chromatog. The method is specific, rapid, and sensitive (∼20 mmol/L). MeOH, ethylene glycol, and iso-PrOH did not interfere with the detn.; propanol, butanol, and AcH did interfere with the detn.