The spectrophotometric multicomponent analysis of a ternary mixture of ascorbic acid, acetylsalicylic acid and paracetamol by the double divisor-ratio spectra derivative and ratio spectra-zero crossing methods.

The double divisor-ratio spectra derivative and ratio spectra-zero crossing methods were applied to the analysis of an effervescent tablet containing the title compounds without using a chemical separation procedure. In the use of both methods, the calibration graphs were linear in the range of 8-28 microg ml(-1) for three compounds. Comparison of the results obtained by the two methods indicates that both methods gives the best results.