The database contains more than 1300 UV-absorption continuous spectra that can be used with Chromalytica and other GC-UV solutions. The information can be supplied in printed format in an indexed binder of about 800 pages and/or on CD ROM. UV spectroscopy is defined as an analytical method that utilizes ultraviolet-visible light to excite electrons in molecules, allowing for the identification of functional groups and the examination of electron transfer among bands or orbitals in various phases of matter. Peaks in UV spectra tend to be quite broad, often spanning well over 20 nm at half-maximal height. Typically, there are two things that we look for and record from a UV-Vis spectrum. Online Spectral Database: Quick access to millions of NMR, IR, Raman, UV-Vis, and Mass Spectra.* Search a compound by name, InChI, InChIKey, CAS Registry Number, or Draw a Structure UV–Vis spectroscopy is routinely used in analytical chemistry for the quantitative determination of diverse analytes or sample, such as transition metal ions, highly conjugated organic compounds, and biological macromolecules. 紫外-可见分光光度法（Ultraviolet–visible spectroscopy，UV-Vis），又称紫外-可见分子吸收光谱法，是以紫外线-可见光区域电磁波连续光谱作为光源照射样品，研究物质分子对光吸收的相对强度的方法。 紫外可见光谱 是利用物质对光的选择性吸收、透射或反射的特性，从而测定、分析、推断物质的组成、含量及结构。 定性分析：判断 共轭关系 及某些官能团。 比如在（200~400）nm之间无吸收峰，说明该未知物无共轭关系，且不会是醛、酮，很可能是一个饱和化合物。 异构体的判断。 例如：乙酰乙酸乙酯存在 酮-烯醇互变异构体。 酮式没有共轭双键，在204nm处有弱吸收；烯醇式有共轭双键，在245nm处有强吸收。 故可根据它们的紫外吸收光谱可判断其存在与否。 纯度检查。 例如，如果一化合物在紫外区没有吸收峰，而其中的杂质有较强的吸收，就可方便检出该化全物中的痕量杂质. 液体、透明薄膜选吸收或透过；粉末、块体、不透明薄膜选吸收或反射。 The UV/Vis spectra collected are taken mainly in the liquid phase (this reflects the nature of the literature the spectra are abstracted from). Consequently the data on the solvent used are included. UV spectroscopy is a type of absorption spectroscopy in which light of the ultra-violet region (200-400 nm) is absorbed by the molecule which results in the excitation of the electrons from the ground state to a higher energy state. Although we see sunlight (or white light) as uniform or homogeneous in color, it is actually composed of a broad range of radiation wavelengths in the ultraviolet (UV), visible and infrared (IR) portions of the spectrum.