Highly selective and sensitive differential pulse voltammetric method based on poly(Alizarin)/GCE for determination of cefadroxil in tablet and human urine samples

Cefadroxil, which belongs to the first-generation cephalosporin class of β-lactam antibiotics, develops bacterial resistance necessitating development of sensitive and selective method for its determination. This paper reports determination of cefadroxil in tablet and human urine samples using poly(alizarin)/GCE. CV and EIS results confirmed deposition of a conductive and electroactive polymer film. Relative to the peak of cefadroxil at the bare electrode, an irreversible oxidative peak at poly(Aliz)/GCE with four folds of current and much reduced potential verified improvement on electrode surface conductivity and effective surface area. DPV current varied linearly with concentration of cefadroxil in the range 1.0 × 10−7–1.0 × 10−4 M with LoD, and LoQ of 8.1 × 10−9, and 2.7 × 10−8 M, respectively. Detection of 99. ± 3.01 and 99.5 ± 2.03% cefadroxil of the 10.0 and 20.0 µM nominal tablet samples, respectively showed agreement between the detected amount and tablet label. Spike recovery in the range 99.5–100.5% in tablet and human urine samples and interference recovery results in the presence of selected potential interferents in tablet sample with percent error of 0.0–4.9% validated the applicability of the method for determination of cefadroxil in real samples. Compared with previously reported works on cefadroxil determination, relatively wider linear range and extremely low limit of detection of the present method along with its excellent accuracy and selectivity make the method an outstanding candidate for determination of cefadroxil in real samples.