Optimization of complex NH3 with Cu2+ ions to determine levels of ammonia by UV-Vis spectrophotometer

Abstract

Abstract Ammonia analysis based on complexing ammonia with Cu2+ ions by UV-Vis spectrophotometry. This research aims to obtain uptake at the maximum wavelength of the copper-ammonia complex, optimum conditions and validation of UV-Vis spectrophotometry. The reaction between Cu2+ ions which are blue with ammonia colorless occur in solution to form complex compounds [Cu(NH3)4]2+ dark blue, the maximum absorbance is obtained at a wavelength of 615 nm. Optimization of the ammonia complexing the Cu2+ ions provide optimum conditions a solution of Cu2+ concentrations of 0.01 M in ammonia concentration of 0.04 M, pH 7, and the optimum time to form a complex occurred in the 30th minute and complex compounds can be stable for 90 minutes (± 1 hours 30 minutes). The analytical method validation ammonia using Cu2+ ions provide linear regression equation y = 4,772 x + 0.333 with R2 = 0.989 ammonia concentration range of 0.003 M to 0.08 M; LOD 0.01 M; LOQ 0.04 M; % RSD = 1.32%; and% recovery = 102.03%. The concentration of ammonia in the wastewater sample application obtained the ammonia concentration of 0.04 M. Based on the results of the validation, Ammonia solution with Cu2+ ion as a complex used for the determination of ammonia levels by UV-Vis spectrophotometry.