Simultaneous Determination of Salicylamide and Paracetamol by Spectrophotometric H-Point Standard Addition Method and Partial Least Squares Regression

Simultaneous spectrophotometric determination of salicylamide and paracetamol by H-point standard addition method (HPSAM) and partial least squares (PLS) calibration is described. The results showed that simultaneous determinations could be performed with the ratio 0.2:5–20:1 for salicylamide – paracetamol. A partial least – squares multivariate calibration method for the analysis of binary mixtures of paracetamol and salicylamide was also developed. The total relative standard error for applying the PLS method to 10 synthetic samples in the concentration range 0–60 μg mL salicylamide and 0–30 μg mL paracetamol was 5.1%. Both the proposed methods (PLS and HPSAM) were successfully applied to the determination of salicylamide and paracetamol in pharmaceutical preparations.