Cyanide analysis based on complexing of CN⁻ ion and spectrophotometry method

Cyanide analysis based on the complexing of CN⁻ with Ni²⁺ ions by UV-Vis spectrophotometry has been performed. This study aims to obtain the maximum wavelength of cyanide-nickel absorption complexes, optimum conditions and UV-Vis spectrophotometric validation. The reaction between the green Ni²⁺ ion and the colorless CN⁻ ion occurs in the solution to form a yellow [Ni(CN)⁴]^2- complex, the maximum absorption is obtained at a wavelength of 308 nm. The optimum condition of [Ni(CN)⁴]^2- complex gave at pH 6 and the concentration of Ni²⁺ solution of 0.001 M at a cyanide concentration of 0.004 M, while the optimum time formed by the complex occurred in 110 minutes and the complex compound was stable for 1390 minutes (± 23 hours 10 minutes). Validation of cyanide analysis method using Ni²⁺ ion gives linear regression equation y = 47,446x - 0,0184 with value R² = 0,9958 at concentration range CN⁻ 0.0003 M to 0.008 M; LOD 0.0006 M; % RSD = 0.97%; And % recovery = 103.8%. Based on the validation results, this method can be used to determine the cyanide content using Ni2+ ions as complexes by UV-Vis spectrophotometry. (paper)