Aspirin Content Comparisons Across Brands Group 102 A

Aspirin Content Comparisons Across Brands Group 102 -A 1 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 325 mg University of Pennsylvania Department of Bioengineering

Methods, Protocol & Equipment: • Construct 3 calibration curves using a spectrophotometer and 1 mg/m. L sodium salicylate • Make dilutions in increments of 0. 05 mg/m. L from 0. 1 mg/m. L to 0. 5 mg/m. L • Force regression through (0, 0) CVS Bayer 3 tablets 5 absorbance readings per each* tablet Ecotrin Convert absorbances to aspirin masses *These tablets will be dissolved to 1000 m. L of solution University of Pennsylvania ANOVA and Bonferroni test Average masses in brands; compare to 325 mg 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 a = 0. 05 Fcrit > Fdet • Less than 5% variation from the manufacturers’ claim of 325 mg for each brand University of Pennsylvania Department of Bioengineering

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

Materials and Budget: • CVS Brand 325 mg Aspirin tablets (100 count) – $1. 99* • Bayer Brand 325 mg Aspirin tablets (100 count) – $5. 79* • Ecotrin Brand 325 mg 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 • 325 mg dosage for proper absorbance range University of Pennsylvania Department of Bioengineering