Document Type : Original Article
İnönü University, Faculty of Science, Department of Chemistry, 44280 Malatya, Turkey
İnönü University, Faculty of Pharmacy, Department of Basic Pharmaceutical Sciences, Division of Analytical Chemistry, 44280 Malatya, Turkey
In this study, the quantitative amount of 5-hydroxyindoleacetic acid (5-HIAA) was determined at poly (p-amino benzene sulfonic acid) (p-ABSA) modified glassy carbon electrode. The redox property of 5-HIAA was investigated by cyclic voltammetry. The cyclic voltammograms showed that the redox reaction of 5-HIAA was irreversible. Scan rate study showed that the redox reaction of 5-HIAA was controlled by both diffusion and adsorption on the poly (p-ABSA) modified sensor. Differential pulse voltammetry technique was used for the quantitative analysis of 5-HIAA in phosphate buffer solution at pH 7.00. The linear working range of the calibration graphs was determined as 1×10-5–9×10-5 M (R2, 0.9912), and the detection limit was determined as 5.3×10-7 M. Recovery values in the analysis of urine samples were between 99.4% and 103.0%. The results showed that the modified sensor can be applied to the determination of 5-HIAA in the presence of ascorbic acid. The proposed sensor is promising for routine analysis due to its high selectivity, reproducibility, long-term stability, and high recovery values in biological samples.