Voltammetric codetection of arsenic(III) and copper(II) in alkaline buffering system with gold nanostar modified electrodes.

Voltammetric codetection of arsenic(III) and copper(II) in alkaline buffering system with gold nanostar modified electrodes. Anal Chim Acta. 2020 Apr 22;1107:63-73 Authors: Sullivan C, Lu D, Brack E, Drew C, Kurup P Abstract One of the challenges preventing rapid, onsite voltammetric detection of arsenic(III) is the overlapping oxidation peak of copper(II). This paper describes a novel methodology for the voltammetric detection of trace levels of arsenic(III) in the presence of high copper(II) concentrations (up to the action level of 1.3 mg L-1 set by the US EPA for drinking water). Square wave stripping voltammetry tests were performed using disposable carbon screen printed electrodes modified with gold nanostars on samples buffered with Britton-Robinson buffer. The optimized parameters for accurate codetection of arsenic(III) and copper(II) were a buffer pH of 9.5, a loading of gold nanostars of 2.39*10-5 nmol per electrode, a deposition voltage of -0.8 V, and a deposition time of 180 s. Based on calibration testing, the limits of detection for arsenic(III) and copper(II) were determined to be 2.9 μg L-1 and 42.5 μg L-1, respectively. Furthermore, the linear ranges for arsenic and copper were 0-100 μg L-1 and 0-250 μg L-1 with sensitivities of 0.101 μA (μg L-1)-1 and 0.121 μA (μg L-1)-1, respectively. Interference testing was performed with several common ionic species, sodium bicarbonate, sodium chlorid...
Source: Analytica Chimica Acta - Category: Chemistry Authors: Tags: Anal Chim Acta Source Type: research