A spectrophotometer is an instrument used to measure how much light a substance absorbs at a particular wavelength. It’s widely used in chemistry, biology, and pharmaceutical analysis.
How it works, step by step:
- Light Source
- The instrument shines light onto the sample.
- The light can be visible, ultraviolet (UV), or infrared (IR) depending on the type of spectrophotometer.
- Monochromator
- This selects a specific wavelength of light to pass through the sample.
- Only the chosen wavelength reaches the sample.
- Sample Holder (Cuvette)
- The sample solution is placed in a transparent cuvette.
- Light passes through the sample, and some is absorbed.
- Detector
- Measures the amount of light that passes through (transmitted light).
- Converts it into an electrical signal.
- Display and Data System
- The instrument calculates absorbance using the transmitted light.
- Results are shown on a screen or printed as a graph (absorbance vs. wavelength).
In short:
A spectrophotometer works by shining light through a sample, measuring how much light is absorbed, and using that information to determine concentration, purity, or other properties of the substance.