Application of differential pulse stripping voltammetry and chemometrics for the determination of three antibiotic drugs in food samples

A reliable method for simultaneous determination of three antibiotic drugs (levofloxacin, gatifloxacin and lomefloxacin) by differential pulse stripping voltammetry (DPSV) in Britton–Robinson buffer (pH 7.96) was presented. The method is based on adsorptive accumulation of the antibacterial drugs on a hanging mercury dropping electrode (HMDE), followed by the reduction of the adsorptive species by the technique of DPSV. Optimal conditions, the deposition time of 80 s, the deposition potential of −1250 mV, and the scan rate of 25 mV/s, were obtained. The linear concentration ranges of 0.010–0.080 μg/mL were obtained for all these three antibiotic drugs, while the detection limits were 2.38, 3.20 and 1.60 ng/mL for levofloxacin, gatifloxacin and lomefloxacin, respectively. In this work, chemometrics methods, such as classical least squares (CLS), partial least squares (PLS), principle component regression (PCR) and radial basis function-artificial neural networks (RBF-ANN), were used to quantitatively resolve the overlapping signals. It was found that PCR gave the best results with total relative prediction error (RPET) of 7.71%. The proposed method was applied to determine these three drugs in several commercial food samples with spiked method and yielded satisfactory recoveries.