Simultaneous spectrophotometric determination of paracetamol and para-aminophenol in pharmaceutical dosage forms using two novel multivariate standard addition methods based on net analyte signal and rank annihilation factor analysis.

Recently we proposed two multivariate standard addition methods using net analyte signal concept and rank annihilation factor analysis, which we named SANAS and SARAF, respectively. These methods could model both indirect sample matrix effects and direct interference effects of the coexisting analytes. Here, the potential of these methods for simultaneous determination of paracetamol and para-aminophenol in the synthetic mixtures and pharmaceutical products was examined. It was found that both models could predict the concentration of analytes in synthetic mixtures with relative errors of prediction lower than 7%. Moreover, the employed methods exhibited the recoveries in the range of 93.11 and 108.67 for analysis of the drugs in the real matrices. From SANAS plots, the figures of merit including sensitivity, selectivity and limit of detection were calculated as 0.143 µg/ml, 0.587 and 0.018 µg/ml for paracetamol and 0.128 µg/ml, 0.547 and 0.020 µg/ml for para-aminophenol, respectively.