Ultraviolet-Visible spectroscopy (UV/VIS) is the oldest form of spectroscopy. It uses light in the visible and adjacent near ultraviolet (UV) and near infrared (NIR) ranges. In this region of energy space molecules undergo electronic transitions. The method is used in a quantitative way to determine concentrations of absorbing species in solution, using the Beer-Lambert law:
- A= ln(I/Io) = ε·c·l