Spectrophotometry

Spectrophotometry is an analytical method of measuring the amount of visable or ultra-violet light absorbed or transmitted by a substance in solution. Concentrations of various substances can also be determined using spectrophotometry and it is a commonly used technique that detects amounts of drugs,proteins and DNA. The amount of light absored is proportional to the concentration of the solute; it is often then possible to construct a standard curve to figure out unknown concentrations. This method has been adopted and used in the study of biochemistry, physics, chemical engineering and more.

All substances in solution absorb light of one wavelength and transmit light of another wavelengths. Absorbance is a characteristic of a substance just like melting point, boiling point, density and solubility. There are two types of spectrophotometers. UV-Visable uses light which range at 185 - 700 nm  and IR spectrophotometers which uses light with a range of 700 - 1500 nm