The Beer Lambert law, also known as the Beer-Lambert-Bouguer law, is a relationship between the concentration of a substance in a solution and the amount of light that is absorbed by that solution. It is commonly used in spectrophotometry to quantify the concentration of a substance in a solution.
The Beer Lambert law states that the absorbance of a solution is directly proportional to the concentration of the absorbing substance and the path length of the light through the solution. This means that as the concentration of the substance increases, the absorbance also increases, and as the path length increases, the absorbance also increases.
The formula for the Beer Lambert law is A = ɛcl, where A is the absorbance, ɛ is the molar absorptivity coefficient, c is the concentration of the substance, and l is the path length of the light through the solution. This formula can be rearranged to solve for any of the variables.
Yes, the Beer Lambert law can be applied at non-normal incidences, meaning that the light is not passing through the solution perpendicular to the surface. However, the path length of the light through the solution may need to be adjusted to account for the angle of incidence.
While the Beer Lambert law is a useful tool for quantifying the concentration of a substance in a solution, it does have some limitations. One major limitation is that it assumes that the light passing through the solution is monochromatic, meaning it has a single wavelength. Additionally, it assumes that the solution is free of any scattering or other interfering substances, which may not always be the case.