Instrumental Methods of Analysis (BP701T): UV, IR, NMR, Mass & Chromatography

Chapter 1: Ultraviolet-Visible (UV-Vis) Spectroscopy

UV-Vis absorption spectroscopy measures electronic transitions of valence electrons from bonding or non-bonding orbitals to anti-bonding orbitals when irradiated with 200 - 800 nm electromagnetic radiation.

Beer-Lambert Law:

\[ A = \log_{10}\left(\frac{I_0}{I}\right) = \varepsilon \cdot b \cdot c \]

Where \(A\) is absorbance, \(\varepsilon\) is molar absorptivity \((L\cdot \text{mol}^{-1}\cdot \text{cm}^{-1})\), \(b\) is path length (1 cm standard quartz cuvette), and \(c\) is molar concentration.