Magnetic circular dichroism fluorescence detection

Electronic spectroscopy (see Electronic Spectroscopy), in one form or another, has been the principal method used for the detection of short-lived intermediates. UV-visible absorption was the initial spectroscopic method used with flash photolysis and flow systems, and for each of these methods it remains the most commonly used approach. For species in low-temperature matrices, many varieties of electronic spectroscopy have been used. These include UV-visible absorption and emission, fluorescence, magnetic circular dichroism (MCD) and magnetic linear dichroism, and photoelectron spectroscopy. It is unfortunate, therefore, that in many cases electronic spectroscopy yields little or no stractnral information. The exceptions are high-resolution spectra, where vibrational or rotational flne structure may be seen. 

Magnetic circular dichroism, a more recent development, has been used mainly in the study of haem proteins and has been reviewed recently as has been fluorescence-detected circular dichroism (FDCD). 

See also Biochemical Applications of Raman Spectroscopy Biomacromolecular Applications of Circular Dichroism and ORD Carbohydrates Studied by NMR Circularly Polarized Luminescence and Fluorescence Detected Circular Dichroism Induced Circular Dichroism Magnetic Circular Dichroism, Theory Nucleic Acids and Nucleotides Studied Using Mass Spectrometry Organometallics Studied Using Mass Spectrometry Polymer Applications of IR and Raman Spectroscopy Proteins Studied Using NMR Spectroscopy Vibrational CD Spectrometers Vibrational CD, Theory. 

Sensitive immunoassays specific for PAH-DNA adducts allow the detection of one adduct per 10 nucleotides. Fluorimetry has also been used as an alternative detection method to immunoassays. In another method, isomeric tetrols of PAH are liberated by acid hydrolysis of the DNA-PAH adducts and analyzed by LC with fluorescence detection. Structural studies and detailed characterization of PAH metabolites and their conjugates has been performed by trapping the corresponding fractions at the exit of the LC system. As an example, the total characterization of the in t /tro-formed benzo(a)pyrenetetra-hydrodiol-epoxide-guanosine adduct has been achieved by a combination of nuclear magnetic resonance, circular dichroism, and mass spectroscopic techniques. 

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