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With this source, Turner's group obtained an energy resolution of 0.02 eV. Turner referred to the method as "molecular photoelectron spectroscopy", now usually "ultraviolet photoelectron spectroscopy" or UPS. As compared to XPS, UPS is limited to energy levels of valence electrons, but measures them more accurately.
UV-Vis can be used to monitor structural changes in DNA. [8] 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. Spectroscopic analysis is commonly carried out in ...
With the aid of these rules the UV absorption maximum can be predicted, for example in these two compounds: [8] In the compound on the left, the base value is 214 nm (a heteroannular diene). This diene group has 4 alkyl substituents (labeled 1,2,3,4) and the double bond in one ring is exocyclic to the other (adding 5 nm for an exocyclic double ...
When an isosbestic plot is constructed by the superposition of the absorption spectra of two species (whether by using molar absorptivity for the representation, or by using absorbance and keeping the same molar concentration for both species), the isosbestic point corresponds to a wavelength at which these spectra cross each other.
This is similar to the situation in a hydrogen flame. Arc lamps made with ordinary light-hydrogen provide a very similar UV spectrum to deuterium, and have been used in UV spectroscopes. However, lamps using deuterium have a longer life span and an emissivity (intensity) at the far end of their UV range which is three to five times that of an ...
For example, EPS is based on the regularities of the correlation of physico-chemical properties and integral spectral characteristics for UV or (and) visible regions of the electromagnetic spectrum (so-called law spectrum-properties). Color is also an integral characteristic of a visible spectrum.
Ultraviolet–visible spectroscopy (UV–vis) can distinguish between enantiomers by showing a distinct Cotton effect for each isomer. UV–vis spectroscopy sees only chromophores , so other molecules must be prepared for analysis by chemical addition of a chromophore such as anthracene .
The vast majority of liquid chromatographic systems are equipped with ultraviolet (UV) absorption detectors. The most common UV-Vis detectors used are variable wavelength detectors (VWD), photo diode array detectors (PDA), and diode array detectors (DAD). [4] Variable wavelength detectors decide in advance which wavelength is needed for the ...