Radical analytical tools

Historically, spin traps have been used as an analytical tool to determine the nature of free radicals being generated in reactions (Janzen, 1971). By design, they react with free radicals to form a stable radical product. They... 

Later, the presence of an organic radical in the green form was revealed by means of a full set of physicochemical analytical tools, namely the UV/vis/NIR... 

Using time-resolved CIDNP [56], the products of the fast geminate reaction may be detected, too. Obviously, the CIDNP effect is predetermined as an analytical tool for the examination of the structure and energetics of radical ions [57], less for ion pairs. 

The effects of irradiation on many different types of substances are now studied at CHAM (Analytical Chemistry Department at the University of Louvain, School of Pharmacy) [2] and in other groups [3]. All the most advanced analytical tools are explored to detect the traces and to study radiosterilization Electron Spin Resonance (ESR) is the most sensitive technique and the spectra were found to be specific to free radicals produced in irradiated... 

Drs. Seehra and Ibrahim summarize recent advances in the important analytical tool of electron spin resonance, particularly as it is used in the direct catalytic liquefaction of coal. This tool is especially important because it can now be used in situ. There is some question about the role of free radicals in direct liquefaction, and the authors explore this subject. 

Among the major analytical tools for detecting and studying radical cations are mass spectrometry, electron spin resonance spectroscopy, nuclear magnetic resonance spectrometry, and particular variations of these methods. 

The MC simulation was performed for 1x10 polymer molecules in each condition [264]. It was shown that both the average number of radicals n and the distribution of the number of radicals per polymer particle agree completely with the analytical solution derived by O Toole [119], and it was confirmed that the present MC simulation can be conducted without significant statistical errors [264]. 

Kiperman [31] also warns that detection of free radicals in the postcatalyst volume in itself cannot serve as concrete proof of their direct participation in the process. The relation also has to be revealed between the nature of these radicals formed in the volume and the intermediates of the true heterogeneous component of the reaction. Obviously, sophisticated analytical and characterization procedures are needed to elucidate the nature of the species reacting on and desorbing from a catalytic surface. A powerful tool to study adsorption and desorption of radicals from surface is laser-induced fluorescence, applied to hydroxyl and oxygen radicals by a number of researchers cf. Ref 37. Such techniques will continue to aid in the elucidation of heterogeneous-homogeneous mechanisms. 

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