Batch and flow injection spectrophotometric methods for the determination of barbituric acid in aqueous samples via oxidative coupling with 4-aminoantipyrine

摘要

A batch and flow injection (FI) spectrophotometric methods are described for the determination of barbituric acid in aqueous and urine samples. The method is based on the oxidative coupling reaction of barbituric acid with 4-aminoantipyrine and potassium iodate to form purple water soluble stable product at λ 510?nm. Good linearity for both methods was obtained ranging from 2 to 60?μg?mL ?1 , 5–100?μg?mL ?1 for batch and FI techniques, respectively. The limit of detection (signaloise?=?3) of 0.45?μg?mL ?1 for batch method and 0.48?μg?mL ?1 for FI analysis was obtained. The proposed methods were applied successfully for the determination of barbituric acid in tap water, river water, and urine samples with good recoveries of 99.92% and 100.67% for batch and FI method, respectively.