UV Spectroscopy Quiz

UV-Vis Spectrophotometry

• A UV-vis spectrophotometer measures the absorption of light in the ultraviolet and visible regions of the electromagnetic spectrum.
• For a sample to be suitable for UV-Vis spectroscopy, it must be able to absorb light in the UV-Vis range, typically having a chromophore, a group of atoms that absorbs light.
• In UV-Vis spectrophotometry, besides the wavelength of measurement, the parameter of interest measured is absorbance, which is a measure of the amount of light absorbed by a sample.
• Most molecules and ions absorb electromagnetic energy in the ultraviolet or visible range, resulting in electronic transitions.
• The amount of light absorbed by a sample in a UV-vis spectrophotometer indicates the presence and concentration of a particular absorbing compound.
• The main function of a UV-vis spectrophotometer is to measure the absorption of light by a sample as a function of wavelength, providing information about the sample's molecular structure.
• A chromophore refers to a group of atoms in a molecule responsible for absorbing light in the UV-Vis range, resulting in a specific absorption spectrum.
• There is a direct relationship between absorbance and the concentration of an absorbing compound in a sample, as described by the Beer-Lambert law.
• Emission spectroscopy is the complementary spectroscopy technique to absorption spectroscopy in UV-Vis spectrophotometry, measuring the emitted light instead of absorbed light.
• The function of an ultraviolet-visible (UV-VIS) spectrophotometer is to quantify the interaction between matter and electromagnetic radiation in the UV-Vis range, providing information about the sample's molecular structure and composition.