1. University of Pennsylvania Department of Bioengineering Aims/Objectives: Compare the mass of aspirin between three brands of tablets Use a calibration curve and spectrophotometric analysis to determine the amount of aspirin in each tablet Hypotheses: There will be no difference between the mass of aspirin in each of the three brands The amount of aspirin in each brand of tablet will vary no more than 5% from the manufacturer’s claim of 325mg Aspirin Content Comparisons Across Brands Group 102-A1

2. University of Pennsylvania Department of Bioengineering Methods, Protocol & Equipment: Construct 3 calibration curves using a spectrophotometer and 1mg/mL sodium salicylate Make dilutions in increments of 0.05mg/mL from 0.1mg/mL to 0.5mg/mL Force regression through (0,0) CVS Bayer Ecotrin 3 tablets each* 5 absorbance readings per tablet Convert absorbances to aspirin masses ANOVA and Bonferroni test Average masses in brands; compare to 325 mg *These tablets will be dissolved to 1000mL of solution

3. University of Pennsylvania Department of Bioengineering Proposed Results/Findings/Deliverables: An average calibration curve with error bars and a regression forced through (0,0) Absorbance values for aspirin will be ~ 0.5 A single factor ANOVA test with  = 0.05  F crit > F det Less than 5% variation from the manufacturers’ claim of 325mg for each brand

4. University of Pennsylvania Department of Bioengineering Potential Pitfalls: Error by spectrophotometer inconsistencies Linear limits of spectrophotometer Any unwanted side reaction of phenol with Fe 3+ reagent  Chipping of tablets, and unwanted loss of mass  Non-uniform concentration throughout salicylic acid solution  Discrepencies due to different microcoatings on all aspirin tablets

5. University of Pennsylvania Department of Bioengineering Materials and Budget: CVS Brand 325mg Aspirin tablets (100 count) – $1.99* Bayer Brand 325mg Aspirin tablets (100 count) – $5.79* Ecotrin Brand 325mg Aspirin tablets (125 count) – $7.39* Total: $15.17 *prices taken on 4-17-2005 at CVS, 3924 Walnut Street Justification: No extra reaction with iron reagent 325mg dosage for proper absorbance range