Tim McCabe, Kelsie Warner, Charlotte Wright.

The purpose of the experiment was to determine the presence of methylparaben and propylparaben in two different brands of oral liquid, Crest and Scope with three bottles of each brand. Solid phase extraction (SPE) and HPLC were used to concentrate and analyze the samples. It was determined that by running the oral liquids through SPE only 2.6% of the parabens were retained. The average concentration of the methylparaben per bottle in the Scope was found to be 35.45 +/- 50.19 mg/bottle and for the propylparaben, the concentration was found to be 3.41 +/- 3.70 mg/bottle. The concentration of Methylparaben per bottle of Crest was calculated to be 32.08 mg/bottle and the concentration of propylparaben was calculated to be 3.43 mg/bottle. Due to concentration errors with the Crest solution and calibration errors with the HPLC data only one Crest sample was determined.