Abstract
We investigated whether the direct spectroanalysis could be used for the determination of the quality of alcohol, and found that the reliability of the result of the analysis was about equal or higher than the sensorial test that had been the only method of final determination of the quality of alcohol.
1. We concluded that the following two methods were fit for above purposes, one was the direct measuring of 100-% transmittance of alcohol at near-ultraviolet region by using water as the standard (Awa.-method), the other was the direct measuring of absorbance at the same region comparing with standard alcohol which was, refined as purely as possible (Aalc.-method).
2. The absorption curve of the standard alcohol by Awa.-method between 2550Å (0%) and 2100Å (36%) showed an almost perfect parabola. Various alcohol tested by Awa.-method showed -the different types of curves which were plotted above this curve by influences of those impuriti-es. So it was found that we could evaluate the quality of alcohol absolutely or relatively by the form and the value of the peak of the curve and that the results were almost parallel to that of the sensorial test.
3. The curve for high class alcohol took place in zone of 2600 A (<5%)_??_2100Å (<55%) by Awa.-method, but the curves obtained by Aalc.-method showed larger differences between each other. Therefore if we could easily have more purified standard alcohol, Aale.-method may be more suitable for the detection of alcohol impurities.
