Simultaneous determination of β-agonists by UHPLC coupled with electrochemical detection based on palladium nanoparticles modified BDD electrode

Abstract

Palladium nanoparticles (PdNPs) modified boron-doped diamond (BDD) electrode was simply fabricated via electrodeposition technique for the sensitive electro-analysis of four β-agonist compounds, including terbutaline (TER), salbutamol (SAL), ractopamine (RAC), and clenbuterol (CLB) after a prior separation by ultra-high performance liquid chromatography (UHPLC). The separation was carried out using a reverse phase C18 column with gradient elution of appropriate proportion between methanol and phosphate buffer solution (PBS) pH 7.0 at a flow rate of 1.0 min mL −1 . The following electrochemical detection (ECD) was accomplished by amperometric method with a detection potential of 1.0 V vs Ag/AgCl. The modified BDD electrode, unlike other carbon-based electrodes used for β-agonists detection, typically showed the superior anti-fouling ability and provided excellent long-term stability, resulting in no complicated cleaning steps needed during each determination. The measurement of β-agonists using the PdNPs modified BDD electrode integrated with UHPLC showed a linear relationship in the range of 0.2 to 200 μg mL −1 with detection limits of 0.04, 0.02, and 0.03 μg mL −1 for TER, SAL, and RAC, respectively. Meanwhile, CLB displayed linearly in the range of 0.5 to 200 μg mL −1 with a detection limit of 0.19 μg mL −1 . Moreover, this method was successfully applied to detect β-agonists in diverse samples, including swine feed, swine meat, and human urine with satisfied recoveries in the range from 80.5% to 110.0%. Reliability of this developed method was also validated with ultra-high performance liquid chromatography coupled with ultra-violet detection (UHPLC-UV), and the results showed highly quantitative agreement between the two methods. Therefore, the PdNPs modified BDD could be productively utilized as effective electrodes, with good electrocatalytic activity of PdNPs towards β-agonists oxidation and favorable anti-fouling performance of BDD. The simultaneous detection of four β-agonists by UHPLC-ECD exhibited good stability, acceptable reusability, high sensitivity and rapid analysis. © 2019