Rapid and simultaneous electrochemical method to measure copper and lead in canine liver biopsy

Abstract

The conventional analytical techniques used for the quantitative analysis of heavy metals in animal tissues are the atomic absorption spectroscopy (AAS) and the inductively-coupled plasma mass spectrometry (ICP-MS). These methods involve high cost, skilled personnel and long analysis times. Several studies have shown the applicability of electrochemical transducer coupled to disposable screen-printed electrodes (SPE) for measuring metals. The aim of the present study was to applicate and validate a simple and fast protocol for the simultaneous measurement of Cu and Pb concentrations in canine liver biopsy, coupling a simple digestion procedure with electrochemical stripping analysis. Square wave anodic stripping voltammetry (SWASV) coupled to disposable SPE was employed as fast and sensitive method for metals detection. Samples were digested with hydrogen peroxide/hydrochloric acid mixture for 1 h coupled to solid phase purification with carbon columns. Instrumental precision, digestion procedure accuracy and limits of detections were evaluated. To validate the proposed method the metal concentrations have also been determined by AAS. Instrumental precision and digestion method accuracy were less than 15.3% and 16.8% for Cu and Pb, respectively. The limits of detection were 10 and 6 mg/kg dry weight in liver samples for Cu and Pb, respectively. The results obtained by the electrochemical method are in agreement with those of the reference method. The obtained results showed a reliable approach for Cu and Pb detection simultaneously with good sensitivity, accuracy and precision. The simple sample pre-treatment together with the low cost makes this approach particularly appealing for Cu and Pb quantification for diagnostic purposes.•Simultaneous determination of Cu and Pb concentrations in canine liver biopsy.•Square wave anodic stripping voltammetry (SWASV) with screen-printed electrodes (SPE) coupled to an acid digestion protocol.•Cu and Pb were measured with a very good sensitivity and accuracy.•Good agreement with AAS reference method.•Low cost, fast and sensitive method for diagnostic purposes.