What is the principle of spectrophotometry?

Spectrophotometry is based on the principle that substances absorb light at specific wavelengths in proportion to their concentration in a solution. When light passes through a sample, some wavelengths are absorbed by the molecules present, while others may pass through or be transmitted. By measuring the intensity of light absorbed, spectrophotometry allows for the quantification of the concentration of a solute in a solution. This relationship is often described by Beer-Lambert Law, which states that absorbance is directly proportional to concentration.

Thus, the principle that it measures the intensity of light absorbed by a solution is fundamental to the technique, making it a powerful tool for determining concentrations in various chemical and clinical analyses. This is particularly useful in fields like biochemistry and clinical chemistry, where understanding concentrations of biomolecules is critical.