Assay of aspirin: Medicinal Chemistry Practical

The best way to assay aspirin is through various methods such as colorimetric analysis, high-performance liquid chromatography (HPLC), UV-VIS spectrophotometry, and spectrophotometric methods. Colorimetric analysis using redox reactions catalyzed by nanoparticles has been validated for the analysis of aspirin concentration in exhaled breath condensate (EBC). HPLC and UV-VIS spectrophotometry methods have been developed for the estimation of aspirin and impurities in aspirin tablets, providing easy and precise measurements. Spectrophotometric methods have also been used for the determination of aspirin, showing good linear correlation and high sensitivity and selectivity. These methods offer reliable and accurate results, making them suitable for research studies, quality control, and routine analysis of aspirin.

Different methods used to assay aspirin include quantitative analytical methods such as the first derivative of the ratio spectra, TLC densitometry, HPLC, spectrometry, direct titration, back-titration, UV-VIS spectrophotometry, and atomic absorption spectrophotometry.
The first derivative of the ratio spectra was used to resolve the overlapping spectra between aspirin and omeprazole. TLC densitometry technique was applied using TLC aluminum silica gel plates, toluene–acetonitrile–methanol as the mobile phase, and UV detection for the simultaneous quantitative analysis of aspirin and omeprazole. HPLC, spectrometry, direct titration, and back-titration were used in a comparative way to determine the correct amount of acetyl salicylic acid in aspirin formulations. UV-VIS spectrophotometry and atomic absorption spectrophotometry were used for the estimation of aspirin, impurities such as salicylic acid, and heavy metal ions in aspirin tablets.