Editor-in-Chief Hatice Kübra Elçioğlu Vice Editors Levent Kabasakal Esra Tatar Online ISSN 2630-6344 Publisher Marmara University Frequency Bimonthly (Six issues / year) Abbreviation J.Res.Pharm. Former Name Marmara Pharmaceutical Journal
Marmara Pharmaceutical Journal 1996 , Vol 12 , Issue 2
Spectrophotometric analysis of ffervescent tablets containing ascorbic acid and acetylsalicylic acid by absorbance ratio method
Mahmure Üstün Özgür
Absorbance ratio method was applied to the analysis of tablets containing ascorbic acid (AA) and acetylsalicylic acid (ASA) without prior separation. In the spectra of the AA and ASA solutions in 0.1 N H2S04 an isosbestic point occured at 233.8 nm. For calculations, as the second wavelength, 243.3 nm, at which the AA shows maximum absorbance was used. A plot of Q= A243.3/ A233.8 versus the fraction of AA mixture, resulted in a straight line (Q1= 8.72 10-3 % AA + 0.379). Absolute cıncentrations of AA and ASA are calculated from the parameters of m and n and the absorptivity at 233,8 nm (23.3 23). The relative standard deviations obtained were 1.15 % and 0.71 % and the average percentage recoveries were 101.1% and 99.4 % for AA and ASA, respectively.

The same procedure has been carried out using 228.5 nm as the maximum absorbance wavelength of ASA, instead of 243.3 nm (Q2= 3.54 10-3 %ASA + 0.773). The relative standard deviations obtained were 1.41% and 0.84% and the average percentage recoveries were 99.7% and 100.2% for AA and ASA, respectively.

To compare the results, the tablets were analyzed with the methods suggested for AA and ASA in USP XXI. The statistical comparison of the results using t and F tests shows that, the differences were not significant at the 95% confidence level. Keywords : Ascorbic acid- Acetylsalicylic acid determination, absorbance ratio method

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