Optimasi waktu reaksi pembentukan kompleks indofenol biru stabil pada uji n-amonia air limbah industri penyamakan kulit dengan metode fenat

Optimization of the reaction time on the formation of indofenol blue complex for N-Ammonia analysis in the tannery wastewater using phenate method has been carried out. The aim of the study was to determine the optimum time for complex formation of indophenol blue. Variations of reaction time were 1; 2; 2,5; 3; and 21 hours. Accuracy and precision were evaluated to determine the feasibility of developing the method. Analysis of N-Ammonia was done by using a spectrophotometry at a wavelength of 630 nm. Optimum reaction time on the formation of indofenol blue complex for ammonia analysis in the tannery wastewater was achieved at a minimum time of 2 hours at the temperature test of 25oC. The accuracy and relative percent different were 90-97% and <5% respectively, met the SNI-6989.30-2005 so that the method was feasible to be developed and used in the laboratory.