Determination of ethanol in serum by an enzymatic PMS-INT colorimetric method

A simple, rapid and accurate colorimetric method for the determination of ethanol in serum was studied. Ethanol is converted to acetaldehyde by alcohol dehydrogenase, and the NADH formed transfers its hydrogen through the phenazine methosulphate-p-iodonitrotetrazolium violet (PMS-INT) system to produce the red formazan which is stable and absorbs at 505 nm. The method correlates very well with an enzymatic-UV method, r=0.98 (p less than 0.001). The precision (95% limits) of the method for samples ranging from 11 to 145 mg/dl was +/-6.6%, and the recovery averaged 99%.