Determination of aspirin and caffeine Results: Identify and mark the signals in the spectra and note the chemical shift values of the methyl resonances in aspirin and caffeine and the methylene resonance in s-trioxane. Using above expression, calculate the weight of aspirin and caffeine in one tablet, and the percentage w/w of each component in one analgesic tablet. Whole tablet weighed = 0.501 Half tablet weighed = 0.270 Mass of s-trioxane = 0.05 RMM of aspirin = 180 RMM of caffeine = 194 RMM of s-trioxane = 90 No. of moles of components = component integral/no. of protons giving signal No. of moles of standard standard integral/ no. of protons giving signal To find out the weight and percentage w/w of Aspirin and Caffience following calculations were made: Aspirin: No of moles of components (x) = ? No of moles of standard = mass of s-trioxane / RMM of s-trioxane = 0.05 / 90 = 0.000555 Component integral = 202.72 No of protons giving signal = 3 Standard integral = 200 No of protons giving signal = 6 Putting values in the above eq.1: x / 0.000555 = (202.72/3) / (200/6) x/0.
