Present screening methods to rapidly detect release of nickel and cobalt ions from metallic surfaces involve colorimetric dimethylglyoxime (DMG)- and disodium-1-nitroso-2-naphthol-3,6-disulfonate–based spot tests with a cotton bud. There is a risk of false-negative test reactions because test outcomes are dependent on the pressure, area, and duration of surface wiping.
The aim of the study was to develop a miniaturized electrochemical device that uses a voltage to accelerate nickel and cobalt release from the tested item and perform an initial validation.
A device was built in plastic, and its performance was investigated using 0.5 mL of test solutions of, respectively, DMG and disodium-1-nitroso-2-naphthol-3,6-disulfonate. Cotton buds that had been wetted in test solution were pressed against different metal surfaces at various voltages (0–9 V) and a range of test durations (0–120 seconds). Duplicate testing for nickel and cobalt release was also performed on a sample of 163 jewelry items.
This novel electrochemical device makes it possible to perform nickel and cobalt ion release testing without rubbing, thereby reducing interindividual differences in testing technique. The nickel testing with the device seemed to be superior to conventional DMG spot testing.
From the *Department of Mechanical Engineering, Technical University of Denmark, Kongens Lyngby;
†National Allergy Research Centre, Department of Dermatology and Allergy, Herlev-Gentofte Hospital, University of Copenhagen, Hellerup, Denmark;
‡Department of Experimental Dermatology and Cosmetology, Jagiellonian University Medical College, Krakow, Poland;
§Division of Dermatology, Department of Internal Medicine, The Ohio State University, Columbus; and
∥St John's Institute of Dermatology, Guy's Hospital, London.
Address reprint requests to Jacob Pontoppidan Thyssen, MD, PhD, National Allergy Research Centre, Department of Dermatology and Allergy, Herlev-Gentofte Hospital, University of Copenhagen, Kildegaardsvej 28, DK-2900 Hellerup, Denmark. E-mail: firstname.lastname@example.org.
M.S.J. and J.P.T. developed a cobalt spot test and sold it to SmarthHealth, Phoenix, Arizona, and receive annular royalties based on net sales. J.P.T. is a Lundbeck Foundation fellow and is supported by an unrestricted grant. The other authors have no funding or conflicts of interest to declare.