Application of Digital Camera and Digital Image Processing Techmique for Molecular Absorption Analysis in the Visible Spectrum

Abstract

A method of molecular absorption analysis in the visible spectrum has been developed that does not need monochromatic light and measuring the absorbance. Instead, pictures of the test color solution are taken using a digital camera. The digital image data are transferred to a personal computer through a capture card or a cable. Tristimulus values (R, G and B) representing image chromaticity are found. A polynomial regression equation is applied to describe the relation between one of the R, G or B tristimulus values and a concentration of the test solution in order to calculate the unknown concentration. A computer program is specially created to process all necessary operations. Solutions of MnO 4 -, Cr 2 O 7 2-, Cu 2+ , Fe 3+ and NH 4 + with low -and high -level concentrations are analyzed with good analytical characteristics.