An Electrochemical Robotic System for Routine Cathodic Adsorptive Stripping Analysis of Ni²⁺ Ion Release from Corroding NiTi Shape Memory Alloys

Abstract

Cathodic adsorptive stripping voltammetry (AdSV) as highly sensitive and selective method for quantifying trace amounts of dissolved Ni 2þ -ions has been integrated into an electrochemical robotic device using the wells of microtiter plates as low-volume electrochemical cells. A three-electrode assembly integrating a Bismuth film-modified glassy carbon electrode as working electrode and a glass capillary for delivering Ni 2þ standard solution in conjunction with an adapted software allowed multiple AdSV measuring cycles to be performed one after the other in the individual compartments of a 24-well microtiter plate. Of advantage for the automation was the possibility of an in-well electrochemical removal of used and a replating of fresh Bi films in between distinct measuring cycles. With optimized parameters for the accumulation of the complex between Ni 2þ -ions and dimethylglyoxime onto the surface of the Bi film electrode and the subsequent stripping procedure, automated adsorptive stripping voltammetry in the established system offered a linear dynamic range of up to 170 nM, a sensitivity of 12 nA/nM Ni 2þ and a limit of of detection of 2.1 nM (N ¼ 16) for the detection of trace levels of Ni 2þ -ions. Automated AdSV certainly is of convenience for studying larger number of samples due to the high-throughput capability of the robotic apparatus. As example, the automatic quantification of Ni 2þ -ion release from electropolished surfaces of NiTi shape memory alloys during corrosion in NaCl solutions is described.

Pyrolyzed Photoresist Carbon Electrodes for Trace Electroanalysis of Nickel(II)

“…The peak current values obtained using different electrodes were reproducible within 5%. This value is comparable to the one obtained with bulk gold substrate and lower with respect to other electroanalytical methods reported in the literature [29][30][31][32][33][34]. It is well known that DMG complexes other metal cations, such as Co(II) [37,40]; for this reason, cobalt is usually considered an interference in the determination of nickel.…”

“…The majority of these studies were performed using the ex situ prepared bismuth film electrode and dimethylglyoxime (DMG) as the complexing agent [30][31][32]. Alves et al proposed a solid bismuth vibrating electrode for the determination of Ni(II) and Co(II) [33].…”

Simultaneous Adsorptive Cathodic Stripping Voltammetric Determination of Nickel(II) and Cobalt(II) at an In Situ Bismuth‐Modified Gold Electrode

“…10 measurements of 0.5 mg L À1 Ni(II) combined with 120 s accumulation time. In both cases a LOD of 40 ng L À1 was achieved which is the lowest value compared with other electroanalytical methods reported in the literature [15][16][17][18][19]. This sensitivity, attributed also to a 10-electron transfer process [39], is associated with excellent repeatability with relative standard deviation (RSD) of 2.2 % based on 20 consecutive measurements of 0.5 mg L À1 Ni(II).…”

“…The majority of these studies were performed using an ex situ prepared bismuth film electrode with bismuth deposited usually onto different carbon substrates [17][18][19], while Alves et al proposed a solid bismuth vibrating electrode for the determination of Ni(II) and Co(II) [20].…”

A Decade with Bismuth‐Based Electrodes in Electroanalysis

“…The individual contributions came from "traditional" propagators of bismuth electrodes from the U.S.A. [71,83], Slovenia [72,85,89], Czech Republic [72,90,96], Poland [78], Greece [72,73,82,87,90], Portugal [75], France [86,92] and the UK [94]; however, the sixth year of contemporary era of electroanalysis with BiEs was also the sign of new research groups appearing over the whole world. Thus, the aboveintroduced "Bismuth Club" -a hypothetical association and so-far unrealized idea of some pioneers in the field -could invite further members from Europe (Germany [70,93], Spain [80], Italy [91], and Serbia [77]), North America (Delaware, USA [76]), and the Far East (China [79,84], Thailand [76]), and Australia [74,81]. Such diversity of the scientific teams involved in the intensive research on BiEs and BiFEs was naturally mirrored in the respective activities.…”