Fundamentals of Colorimetry

Abstract

There are several kinds of analytical techniques following the principle of photometry in which colorimetry comes under absorption photometry. The colorimetry is commonly used analytical technique involved in quantitative estimation of color i.e. it is utilized to find out concentration of the colored substance in the sample solution e.g. water, biological samples at visible spectrum of light (380–780 nm). The colorimeter is an instrument in which this technique is used. It is also called absorptiometer. A substance must be colorful or should have property of forming chromogens through the addition of reagents which will absorb light according to their color intensity to be measured. The intensity of the color is in proportion to the concentration of colored compound. Most of the analytical techniques used in our clinical laboratory presently are based on this photometric principles in which absorbed, transmitted or emitted light are measured. When intensity at different wavelength on the whole range of electromagnetic spectrum is measured, it is called spectrophotometry. Smartphone accessories have been evolved to allow the simple, quick reproducible values of the molecules.