cuvetta

A cuvette is a small, optically transparent container used in spectroscopy to hold a sample. Cuvettes typically have a square cross-section and are made of glass, quartz, or plastic. The choice of material depends on the wavelength of light being used. Quartz is preferred for ultraviolet (UV) spectroscopy because it transmits UV light, while glass and plastic absorb it. Plastic cuvettes are inexpensive and disposable, often used for routine assays or when contamination is a concern.

The path length, the distance the light travels through the sample, is usually a standard 1 cm. This allows for easy comparison of absorbance values. When using a cuvette, it is important to ensure that the outer surfaces are clean and free of scratches or fingerprints, as these can scatter light and affect the measurement. The cuvette is placed in a spectrophotometer, where a beam of light passes through the sample, and the amount of light absorbed is measured. This information is used to determine the concentration of the analyte in the sample through Beer-Lambert Law. Cuvettes are essential tools in analytical chemistry, biochemistry, and environmental science for a wide range of quantitative analyses.