spektrofotometriu

Spektrofotometrija is a quantitative spectroscopic method that measures the amount of light absorbed by a sample at specific wavelengths. It is a fundamental technique in analytical chemistry, biochemistry, and many other scientific disciplines. The core principle relies on the Beer-Lambert Law, which states that the absorbance of a solution is directly proportional to the concentration of the analyte and the path length of the light through the sample.

A spectrophotometer is the instrument used for this measurement. It typically consists of a light source (e.g., a tungsten lamp or deuterium lamp), a wavelength selector (monochromator or filter), a sample holder (cuvette), and a detector. The light source emits light across a range of wavelengths, which is then passed through the wavelength selector to isolate a specific wavelength. This monochromatic light then travels through the sample, where a portion of it is absorbed. The remaining light intensity is measured by the detector. By comparing the intensity of the incident light to the transmitted light, the absorbance can be calculated.

Spektrofotometrija is widely used for determining the concentration of substances in solution, identifying unknown compounds based on their absorption spectra, and studying reaction kinetics. Common applications include measuring the concentration of proteins, DNA, and enzymes in biological samples, analyzing the composition of food and beverages, and monitoring the purity of pharmaceuticals. The accuracy of spektrofotometriu depends on factors such as the quality of the instrument, the purity of the sample, and proper calibration.