Nickel Assay Kit

Nickel acts as a cofactor for several enzymes, including some ureases, carbon monoxide dehydrogenases (methane forming enzymes which reduce CO₂ to CH₄), and some hydrogenases. Nickel forms complexes with sulfhydryl compounds with significant absorbance in the UV/visible region in the presence of other ions.

In the Nickel Assay kit, Ni²⁺ reacts with 2-mercaptoethanol in borate buffer to form a complex with strong absorbance bands from 300 to 600 nm. Fe²⁺ and Co²⁺ interfere with the assay; therefore, extra steps must be taken to subtract the interference in order to determine the correct nickel concentration in mixed samples. Other ions tested (Mn²⁺, Cu²⁺, and Zn²⁺) do not interfere with the assay and presumably no other ionic species will be present in high enough concentration to interfere with the reaction. The assay is a simple method of quantifying Ni²⁺ in a variety of samples, which gives a linear range of 2–50 nmole nickel in samples containing <25 nmole of Co²⁺ ions.

Suitable for quantifying nickel concentrations in a variety of samples.

In the Nickel Assay kit, Ni²⁺ reacts with 2-mercaptoethanol in borate buffer to form a complex with strong absorbance bands from 300 to 600 nm. Fe²⁺ and Co²⁺ interfere with the assay; therefore, extra steps must be taken to subtract the interference in order to determine the correct nickel concentration in mixed samples. Other ions tested (Mn²⁺, Cu²⁺, and Zn²⁺) do not interfere with the assay and presumably no other ionic species will be present in high enough concentration to interfere with the reaction. The assay is a simple method of quantifying Ni²⁺ in a variety of samples, which gives a linear range of 2–50 nmole nickel in samples containing <25 nmole of Co²⁺ ions.