DIRECT VAPOR GENERATION FOURIER-TRANSFORM INFRARED SPECTROMETRIC DETERMINATION OF ETHANOL IN BLOOD

A new procedure is proposed for a direct determination of ethanol in p lasma and whole blood. The method is based on the injection of a discr ete sample volume of 10 mu l into an electrically heated Pyrex glass r eactor in which, at a temperature of 90 degrees C, the ethanol is vola tilized and introduced by means of a N-2 carrier flow inside a long-pa th infrared gas cell and the corresponding flow analysis recording reg istered as a function of time. The measurement of the area of the flow injection recording, obtained from the absorbance of the transient si gnal in the range 1150-950 cm(-1), allows the direct quantification of ethanol upto 2 gl(-1), with a limit of detection of 0.020 g l(-1) and coefficient of variation between 0.3 and 1.9% for three replicate ana lyses of the same sample. The analysis frequency of the method is 40 h (-1), and it can be applied to a single drop of finger blood.