Summer Undergraduate Research Experience

Last week Dominican University hosted a Summer Undergraduate Research Experience for community college sophomores who wanted a week-long assortment laboratory experiences. For my part, we did an analysis of energy drinks. This experiment was adapted from the “caffeine extraction” sophomore organic chemistry laboratory sequence. First, we did a colorimetric array for each of 6 different energy drinks in a battery of 24 different indicators. The second session was comparing the list of ca_monster2ingredients for the six different brands. We did some internet research on the identity and probably usefulness of the ingredients. In afternoon session we did the extraction of caffeine from energy drinks with liquid-liquid extraction. We analyzed our products by TLC and UV. We also prepared samples for HPLC. In addition to liquid-liquid extraction we performed a solid phase extraction (SPE) of energy drinks. We passed 20 mL of energy drink through an equilibrated 3 mL C18 column, washed the column with water, and eluted the caffeine with methanol. I was very informative to compare the HPLC of 1) the original energy drink, 2) the caffeine extracted by liquid-liquid extraction, 3) the aqueous fraction from the liquid-liquid extraction, and 4) the SPE methanol fraction. In brief there were two or three compounds detectable with HPLC (260nm) in the SPE fraction that were not present in the liquid-liquid extract.

One Comment

  1. Don Shelly
    Posted June 1, 2009 at 7:09 am | Permalink

    Could you please send me a copy of your work. I am very interested in your SPE results, especially compounds seen in SPE extract and not in liquid-liquid extract.


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