sample solution, chromatographic determination of ethanol in the calibration solution, preparation of the sample solution by diluting the alcoholic beverage in water, preparation of the calibration solution, and purity of ethanol used for preparing the calibration solution. Because the same sample solutions were chromatographed on HPLC–FID and GC–FID, the differences in the combined uncertainty were due to the differences of uncertainty concerning the chromatographic determination of ethanol in both the calibration solution and the sample solutions. Although
the HPLC–FID system used was a laboratory-made system, the repeatability of the determnation of ethanol by HPLC–FID was almost same as that by GC–FID.