spectrophotometrie

Spectrophotometry is a technique used to measure how much light a chemical substance absorbs. It is based on the principle that every substance has a unique absorption spectrum, meaning it absorbs specific wavelengths of light. A spectrophotometer is the instrument used to perform this measurement. It works by passing a beam of light through a sample and then measuring the intensity of the light that is transmitted through the sample. The amount of light absorbed is then calculated.

The key components of a spectrophotometer include a light source, a monochromator, a sample holder, and a detector. The light source emits a broad spectrum of light, which is then passed through the monochromator. The monochromator selects a specific wavelength of light to be transmitted to the sample. The sample is placed in a cuvette, which is a small container made of a transparent material. The detector measures the intensity of the light that passes through the sample.

Spectrophotometry is a versatile technique with applications in various fields. In chemistry, it is used for quantitative analysis to determine the concentration of a substance in a solution. It is also used in biochemistry to study the properties of biomolecules like proteins and nucleic acids. In environmental science, it can be used to monitor water quality by measuring the concentration of pollutants. Furthermore, it finds use in industries like pharmaceuticals for quality control and in materials science for characterizing optical properties. The Beer-Lambert law is a fundamental principle that relates the absorbance of light to the concentration of the substance and the path length of the light through the sample, which is often applied in spectrophotometric analysis.