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Experiment 35 Quantitative Ethyl Alcohol Determination by Gas Chromatography

For the quantitative determination of ethyl alcohol, a calibration curve is constructed by plotting the ratio of the ethyl alcohol peak area over the n-propyl alcohol interval standard peak area against the ethyl alcohol concentration. The best-fit straight calibration line can then be determined by visual graphical construction or by manual calculation with a scientific calculator, calculating the best fit by means of least squares, or by employing an electronic spreadsheet. The concentration of the unknown is calculated by determining the ratio of the unknown ethyl alcohol peak area to the internal standard peak area either graphically or by applying the regression equation.