Spectrophotometry is an analytical technique used to measure how much light a substance absorbs. It helps identify and determine the concentration of a chemical in a solution.
Here’s how it works:
1. Basic idea
Every substance absorbs light at specific wavelengths.
When light passes through a solution, some of it is absorbed by the molecules, and the rest passes through.
The spectrophotometer measures how much light is absorbed.
2. How it works
- A light source shines through the sample.
- A monochromator or filter selects a specific wavelength of light.
- The light passes through the sample in a small container called a cuvette.
- A detector measures the amount of light that comes out.
- The instrument calculates how much light was absorbed by the sample.
3. What it tells us
The amount of light absorbed is related to the concentration of the substance in the solution.
Higher concentration → more light absorbed.
Lower concentration → less light absorbed.
4. Uses
Spectrophotometry is used in many areas:
- To measure the concentration of chemicals in laboratories
- To check purity of substances
- To study proteins, DNA, and enzymes in biology
- To monitor pollution in water or air
In short:
Spectrophotometry measures how much light a substance absorbs at a certain wavelength.
It helps identify substances and determine their concentration in a solution.