Adsorptive Stripping Analysis of Trace Nickel at Iridium-Based Ultramicroelectrode Arrays

Joseph Wang* Jianyan Wang, and William K. Adeniyi+
Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003, USA

Samuel P. Kounaves*
Department of Chemistry, Tufts University, Medford, MA 02155, USA

*Authors to whom correspondence should be addressed.
+Permanent address: Department of Chemistry, North Carolina Agricultural and Technical State University, Greensboro, NC 27411, USA

Lithographically-fabricated iridium-based mercury microelectrode arrays are shown to be very suitable for adsorptive stripping measurements of trace nickel in the presence of the dimethylgloxime complexing agent. Variables affecting the response have been assessed and optimized. The sensor optimization has resulted in a favorable and highly stable response, with good linearity and precision (RSD=1.7%), and a low detection limit (0.5 mg/l with 30 sec adsorption). Such adsorptive stripping performance makes the iridium-based microelectrode array very attractive for on-site measurements of trace metals that cannot be plated electrolytically.