Flow Injection Analysis of N-acetyl-L-cysteine Based on the Reduction of Copper(II)-neocuproine Reagent

ABSTRACT

A novel flow-injection analysis spectrophotometric procedure for the determination of N-acetyl-L-cysteine in pharmaceutical formulations is reported. The method is based on the reduction of Cu(II)-neocuproine to Cu(I)-neocuproine by the sulfhydryl group of N-acetyl-L-cysteine in aqueous solution at pH = 3. The absorbance of the yellow Cu(I)-neocuproine complex was measured at 458 nm. The primary chemical and instrumental variables were examined thoroughly. The method was validated in terms of linear dynamic range, limit of detection, limit of quantitation, selectivity, precision, and accuracy. Measurements confirmed its suitability for the reliable determination of N-acetyl-L-cysteine in pharmaceutical preparations at a sampling rate of 180 analyses per hour.

KEYWORDS:

• Cu(II)-neocuproine reagent
• flow-injection analysis
• N-acetyl-L-cysteine
• spectrophotometric determination