Spectrophotometry

Spectroscopy is the study of the interaction of light with matter. By observing how light interacts with matter—through reflection, refraction, elastic scattering, absorbance, inelastic scattering, and emission—it is possible to (1) identify the wavelengths of light that interact with atoms and molecules, or (2) quantify the amount of light being absorbed, reflected, scattered, or emitted at a particular wavelength. This unit describes the background and basic principles of spectrophotometry (the study of the reflection or transmission properties of a substance as a function of wavelength), in particular, absorbance spectrophotometry. Also included is discussion of key spectrophotometer components and their functions, the relationship between absorbance and transmittance, experimental considerations, and the steps necessary in preparing a standard curve for determining absorbance concentration. Curr. Protoc. Essential Lab. Tech. 6:2.1.1-2.1.28. © 2012 by John Wiley & Sons, Inc.