Question

GC-FID system having 10% Trifluoropropyl methyl di-methyl-polysiloxane as a stationary phase is used to separate components of a sample having 100 ppm decane and 100 ppm hexanol in acetone. At initial settings, decane is coming out at 4 mins (completely separated from acetone) and hexanol at 20 mins. The disadvantage of this run is that it is too long. Select all applicable suggestions that can reduce the retention time of hexanol. (Note: Trifluoropropyl forms hydrogen bonding with hexanol acting as hydrogen bond acceptor) Use oven program to increase the temperature after 4 mins into the run Derivatize hexanol, using esterification reaction with acetic acid, to form hexyl acetate Replace stationary phase with another having a lower percentage of Trifluoropropyl groups Increase the flow rate of the mobile phase Reduce the flow rate of the mobile phase Use oven program to reduce the temperature after 4 mins into the run Replace stationary phase with another having a higher percentage of Trifluoropropyl groups Increase the split ratio Change the solvent from acetone to hexane Reduce the length of the column