What are the applications of UV-Vis spectroscopy?

There are various applications of UV-Vis spectroscopy. It is widely used for DNA and RNA analysis, allowing for quick verification of their purity and concentration. This involves assessing the absorbance of light at specific wavelengths, typically 260 nm and 280 nm. The 260/280 absorbance ratio is a key indicator, with pure DNA showing a ratio around 1.8 and pure RNA around 2.0. Deviations from these ratios can indicate contamination (such as from proteins) which absorb more at 280 nm, thus lowering the 260/280 ratio. UV-Vis spectroscopy also plays a crucial role in bacterial culturing by facilitating rapid measurements of optical density (OD) at a wavelength of 600 nm; this measurement is utilized to estimate cell concentration and monitor bacterial growth. One common application in pharmaceuticals involves processing UV-Vis spectra through mathematical derivatives. This helps separate overlapping absorbance peaks in the original spectra. This technique enables the identification of individual pharmaceutical compounds. For instance, benzocaine and chlortetracycline can be simultaneously identified in commercial veterinary powder formulations by applying mathematical derivatives to their absorbance spectra. By creating calibration functions for each compound, it is possible to quantify both substances simultaneously within a microgram per milliliter concentration range. UV-Vis spectroscopy is also frequently utilized to identify specific compounds in beverages, including the quantification of caffeine content to ensure compliance with legal limits. Additionally, UV-Vis spectroscopy enables the identification of various colored substances, such as anthocyanins found in fruits like blueberries and raspberries, by comparing their known peak absorbance wavelengths in drinks like wine. This application serves as a type of quality control in beverage production. UV-Vis spectroscopy is also used in the monitoring of transformer oil for electrical safety by measuring the color index. In cancer research, UV-Vis spectroscopy is utilized to measure the absorbance of hemoglobin for determining hemoglobin concentrations.