Analysis of Ethanol in Beer Using Gas Chromatography: A Side-by-Side Comparison of Calibration Methods

An important objective of any analytical chemistry course is for students to generate and interpret data from the analysis of complex, real-world samples in order to assess the effectiveness of the analysis method, including the calibration. In this laboratory exercise, students directly compare calibration methods (external standards and standard addition, both with and without an internal standard) for the determination of ethanol in beer using an affordable benchtop gas chromatograph. The experiment allows students to evaluate the advantages and disadvantages of each method (including accuracy, precision, and sample preparation) using their own data.