Spectrophotometry /(?)/

Spec·tro·pho·tom·e·try

Spectrophotometry

n.
  1. The art of comparing, photometrically, the brightness of two spectra, wave length by wave length; the use of the spectrophotometer.
  2. the art or process of measuring the degree of absorption of light at different wavelengths by a chemical substance, by means of a spectrometer or spectrophotometer. It is a technique for chemical analysis. (Chem., Physics)