Determination of aspirin and caffeine

Determination of aspirin and caffeineResults make out and mark the signals in the spectra and nary(prenominal) the chemical substance shift values of the methyl resonances in aspirin and caffeine and the methylene resonance in s-trioxane. utilise above expression, calculate the weight of aspirin and caffeine in unrivalled anovulatory drug, and the percentage w/w of distributively comp peerlessnt in oneness analgesic tablet.Whole tablet weighed = 0.501Half tablet weighed = 0.270Mass of s-trioxane = 0.05RMM of aspirin = 180RMM of caffeine = 194RMM of s-trioxane = 90No. of moles of components = component intrinsic/no. of protons well-favoured signalNo. of moles of standard standard integral/ no. of protons adult signalTo find out the weight and percentage w/w of acetylsalicylic acid and Caffience following calculations were madeAspirinNo of moles of components (x) = ?No of moles of standard = mount of s-trioxane / RMM of s-trioxane= 0.05 / 90 = 0.000555Component integral = 20 2.72No of protons giving signal = 3 mensuration integral = 200No of protons giving signal = 6 putting values in the above eq.1x / 0.000555 = (202.72/3) / (200/6)x/0.000555 = 67.57 / 33.33x = 67.57 x 0.000555 / 33.33x = 0.00113 molesMass of aspirin = moles x RMM= 0.00113 x 180 = 0.203g = 203mg% w/w of aspirin in the tablet = mass of aspirin / mass of the tablet x 100= 0.203 / 0.501 x 100= 40.5%CaffeineNo of moles of components (x) = ?No of moles of standard = mass of s-trioxane / RMM of s-trioxane= 0.05 / 90 = 0.000555Component integral = 14.0No of protons giving signal = 3Standard integral = 200No of protons giving signal = 6Putting values in the above eq.1x / 0.000555 = (14.0/3) / (200/6)x/0.000555 = 4.66 / 33.33x = 4.66 x 0.000555 / 33.33x = 0.0000775 molesMass of caffeine = moles x RMM= 0.000075 x 194 = 0.0145g = 14.5 mg% w/w of aspirin in the tablet = mass of aspirin / mass of the tablet x 100= 0.0145 / 0.501 x 100= 2.89%Discussion remark on the chemical shift positions of the m ethyl groups in aspirin and caffeine.Aspirin shows about 6 singlets in the spectrum, all in different environment. It has got one methyl group which gives rise to a singlet at ? 2.3498 as there are no neighbours and the n+1 rule is followed. It has integral of 3 as tierce protons are giving rise to the chemical shift at ? 2.3498. The four singlets between ? 7.1292 ? 8.1123 correspond to benzene think protons. In aspirin there is a very broad singlet at ? 11.0082 receivable to the carbonyl next to hydroxyl proton which shifts it towards the left cut into side.Caffeine has got three methyl groups which give rise to three singlets as all the three methyl groups are in different environments to each other. All the three peaks have integral of 3 which arises due to the three protons on each methyl groups. The first singlet at ? 3.4133 is due to the protons (a) next to nitrogen with single bond. The second singlet is seen at ? 3.5910 synonymic to protons(c) next to double bonded carbon and oxygen and the last methyl singlet (b) at ? 4.004 is due to the protons next to devil double bonded oxygens attached to two carbons. There is also a singlet seen at ? 7.5172 that arises due to a single proton CH between two nitrogens.Compare your results to the contents claimed by the producer and discuss any differences observed.How does this method compare with determinations by UV absorbance and HPLC. What are the proton magnetic resonance methods limitations?UV techniques are simple and rapid. It posterior be utilize for the quantitative determination of highly conjugated compounds and metal ions. Metal ions cigarette be coloured and determined by UV. HPLC is a separation techniques employ for compounds on basis of their rate of elution and can separate complex mixtures. HPLC depth psychology is very quick with high resolution. The stationary column can be used repeatedly for number of times. In HPLC analysis, automated instrumentation and quantitation can be us ed. It also has low sensitivity and accuracy. NMR is an expensive technique. Compared to UV and HPLC the instrumentation is more costly. The sample to be analyzed has to be poverty-stricken of any contaminants. It takes longer time as compared to the other techniques mentioned. In NMR the chemical shift corresponds to the structure of the molecule being analysed so for compounds with interchangeable structures it is difficult to separate the signals. Also it is an insensitive technique.Referenceshttp//www.pg.gda.pl/chem/CEEAM/Dokumenty/Warsztaty/Levsen.pdfhttp//wiki.answers.com/Q/Advantages_and_disadvantages_of_HPLChttp//www.answers.com/topic/hplc-high-performance-liquid-chromatographyhttp//www-unix.oit.umass.edu/mcclemen/581Proteins.htmlhttp//wapedia.mobi/en/Ultraviolet-visible_spectroscopyhttp//books.google.co.uk/books?id=Dvoeg3erhRECpg=PA297lpg=PA297dq=limitations+of+ nuclear magnetic resonance+spectroscopysource=blots=ea8zhh6QdCsig=v3mtaKE11Git3TMIX06mK3KD3yIhl=enei=BStBS5abEJ j20wTkg6mSBQsa=Xoi=book_resultct=resultresnum=6ved=0CBoQ6AEwBTgKv=onepageq=limitations%20of%20nmr%20spectroscopyf=false