Brief Background: For this study, three samples will be examined.  A sample of pure methylene chloride (our solvent) will be examined to see what peaks the solvent may form.  A standard solution of caffeine and methylene chloride will allow the user to determine when caffeine elutes, and provide a clean spectrum of caffeine as well.  In the third sample, an extraction of coffee’s components (particularly caffeine) in methylene chloride is examined, with the previous two assays aiding in identification of the peaks.

The Experiment: In this case study, the goal will be to locate the caffeine peak in the total ion chromatograph.  It may also be helpful to consider the single ion chromatogram.  Determine the retention time of caffeine in the extract sample, and decide if there are components eluting at the same time.