Determination of Ethanol in Solutions by Gas Chromatography, Ramirez, Kevin
College of Science and Mathematics
Professor: Dr. Robert Towery
A Shimadzu Gas Chromatograph 2014 equipped with a Zebron column was used to evaluate the percent ethanol content of prepared ethanol standards as well as collected ethanol containing samples of both known and unknown ethanol content. From the prepared ethanol standards, it was determined that the equation of the line for the calibration curve was y = 1100049.7351x + 1157403.1115 with an R2 value of 0.9987. With this calibration curve and the equation of the line, a sample of known ethanol content, McCormick lemon extract, was evaluated and found to have a mean percent ethanol of 50.63622. From this value, it was then determined that the percent error present in the McCormick lemon samples was 38.99%. This gross error was then attributed to the fact that the McCormick bottle was old and left to sit on a shelf for an extended period of time, allowing ethanol to volatilize out of solution. Two other collected samples, later referred to as ED 32 and ED io, were also run on the GC to determine their percent ethanol content. However, since their true percent ethanol contents were unknown, it was decided that their values were to be expressed as a range of possible percent ethanol contents. From experimentation, it was found that ED 12 had a percent ethanol content in the range of 1.16 – 3.22 % ethanol and ED io had a percent ethanol content in the range of 8.89 – 12.81 % ethanol.
