SIMPLE FLOW INJECTION SPECTROPHOTOMETRIC DETERMINATION OF ACETAMINOPHEN IN PHARMACEUTICAL FORMULATIONS USING 1,2-NAPHTHOQUINONE-4-SULPHONATE AS CHEMICAL DERIVATIZATION CHROMOGENIC REAGENT

Abstract

A simple method for the determination of paracetamol (acetaminophen) with sodium 1,2-naphthoquinone-4-sulphonate (NQS) in alkaline medium using flow injection analysis (FIA) was developed and validated. The effect of variables such as flow rate, NQS concentration, reaction coil length, NaOH concentration, and detection wavelength were studied. Linear response was found over the concentration range 3–35 mg L⁻¹ (r² = 0.9995), the relative standard deviation from replicate injections (n = 9) of 20 mg L⁻¹ of paracetamol was 0.89%. A sampling rate of 82 samples h⁻¹ was obtained. The method was applied for the determination of paracetamol in pharmaceutical tablets, and results have been compared with those obtained by the official method.

ACKNOWLEDGMENT

The authors thank and gratefully appreciate financial support by the Universiti Sains Malaysia (USM) under Science Fund Grant No. 1001/PKIMIA/811055.

Notes

*t-test at 95% confidence level, tabulated t = 2.78.

*{(Present method–Comparison method)/Present method} × 100%.