Colorimetric Determination of Paracetamol Using 9-Chloroacridine Reagent: Application to Pharmaceutical Formulations
Firas Hassan Awad, Department of Pathological Analysis, Al-Qalam University College, Kirkuk, Iraq.
Journal Title:Aalborg Academy Journal of Medical Sciences
Background: The majority of reported spectrophotometric methods for determination of paracetamol are depended on hydrolysis of the compound and applying oxidative coupling and diazotization coupling methods leading to the determination of produced p-aminophenol by different reagents. In addition to using of other methods such as Schiff bases formation, oxidation reaction and charge transfer complex formation reactions. However, some of these methods either not sensitive, carried on organic medium or suffered from interferences. Other analytical techniques have been also used for determination of paracetamol, such as HPLC, voltammetry, chemiluminescence in addition to the titrimetric method. These methods needed of highly sophisticated instruments. Aim: To develop a simple and accurate method for determination of acetaminophen in pharmaceutical formulations. Materials and methods: The method is based on the reaction between the hydrolyzed paracetamol and 9-chloroacridine reagent (9-CA). Results: The spectra of the product show maximum absorption at 436 nm. Beer’s law is obeyed in the concentration range of 0.25-11 μg/ml with molar absorptivity value 5.3×103 L/ mol. cm. The average recovery percentage (Rec%) is 99.27% and relative standard deviation (RSD) is ≤2.82 %. In addition, the stability constant has been determined and the reaction mechanism is proposed. Conclusion: A simple, sensitive and accurate spectrophotometric method is developed for the quantitative determination of paracetamol. The method has been applied successfully for the assay of paracetamol in pharmaceutical formulations. Keywords: Acetaminophen, Paracetamol; 9-Chloroacridine; Spectrophotometry