What Is the Absorption Coefficient?

When light travels through a medium, the phenomenon that the intensity of the light decays with the distance traveled (depth of penetration) is called light absorption. The absorption of light follows the law of absorption (Bill-Lambert's law). The absorption coefficient is a constant in Beer-Lambert law, the sign bit , is called the medium's absorption coefficient of the monochromatic light.

At a given wavelength, solvent, temperature and other conditions, the

The absorption coefficient refers to the absorbance of a light-absorbing substance at a unit concentration and a unit thickness. Two methods are commonly used: molar absorption coefficient and percent absorption coefficient. Molar absorption coefficient refers to the

The absorption coefficient can be measured photometrically. Spectrophotometry is a type of analysis method that utilizes the characteristics of light absorption and the extent of absorption by a substance for qualitative and quantitative analysis. According to the different light sources used in the measurement, the spectrophotometry can be divided into visible first spectrophotometry, ultraviolet first spectrophotometry, and infrared spectroscopy. Spectrophotometry has high sensitivity and is especially suitable for the determination of trace components. At present, the determination of trace components can reach the order of 1 to 10 g / L. If it is separated and enriched in advance, it can determine substances with less content. The relative error of the spectrophotometric measurement is generally 2 to 5%, and the precision instrument can be reduced to 1 to 2%, which can fully meet the requirements for the determination of trace components.

Absorption coefficient ultraviolet spectrophotometry

Ultraviolet spectrophotometry is a qualitative, quantitative, and structural analysis method based on the absorption characteristics of substance molecules for electromagnetic waves in the range of 200nm-400nm. Simple operation, high accuracy and good attention. Light with a long wavelength (low frequency) has less energy, and light with a shorter wavelength (high frequency) has more energy. Spectrophotometry is a measurement of the extent to which molecules of a substance absorb radiation at different wavelengths and at specific wavelengths. ^[3]

Absorption coefficient infrared spectrophotometry

Infrared spectrophotometry is a qualitative, quantitative, and structural analysis method based on the absorption characteristics of substance molecules for electromagnetic waves in the range of 900nm-2500nm.

Absorption coefficient visible light spectrophotometry

Visible light spectrophotometry is a qualitative, quantitative, and structural analysis method based on the absorption characteristics of substance molecules for electromagnetic waves in the wavelength range of 400nm-780nm.