Iron Determination by Colorimetric Method Using O-Phenanthroline

Abstract

Fe2+ reaction with 1, 10-Phenanthroline determined the quantity of soluble iron (II) in the sample to transform a weakly colored iron into an intensely colored complex which could be used in the analysis. The substance absorbed certain wavelengths when a light from the source with a certain intensity and frequency range was passed to this intensely colored complex. The intensity of a solution's color is proportional to the absorbing species concentration and the absorption is proportional to the substance concentration. A separate concentration of standards was prepared and absorbance in 511 nm, the largest wavelength, was determined using Colorimeter. Using the same standard technique and reagents, a blank and three unknown samples were also prepared. A calibration curve was built following Beer's Law. The iron concentration was verified using the equation of the calibration curve and the absorption under the same experimental conditions of three unknowns.