SPECTROPHOTOMETER

•  It is an instrument used to measure the amount of absorbance of light by a sample.
•  It is used to measure the absorbance of light by placing samples in a cuvette in the instrument
•  It was invented by Arnold J. Beckman and his colleagues at National Technologies Laboratory (NTL) in 1940.

Principle:

It is used to measure the light intensity as a function of wavelength. The diffraction of light by a prism into different wavelengths was detected by the charged couplers or detectors.

Instrumentation:

1. Energy source
2. Monochromator- used to break polychromatic radiation into its component wavelengths.
3. Prism- types used are 600 Cornu quartz prism and 300 Littrow prism.
4. Grating- used in monochromators of instruments operating in the ultraviolet, visible, and infrared regions.
5. Cuvettes- It is made up of quartz material where the samples are loaded and placed in the instrument for operation.
6. Detector- It is based on photoelectric current and is amplified and recorded.

Applications:

• detection of the concentration of substances.
• detection of impurities.
• monitoring of dissolved oxygen.
• characterization of protein.
• detection of functional proteins.
• molecular detection of compounds.