Common Radical Analysis

A typical characteristic of most radicals is their high reactivity so they normally have a short life. As a consequence, they may be present only in rather low concentrations so they may be difficult to analyse. Therefore, the spin-trapping technique was developed to detect short-lived radicals. Figure 7 shows an example of this technique in which the reagent PBN (a-phenyl-N-t-butylnitrone; not itself a radical)

Figure 8 ESR spectra of a paramagnetic PBN adduct after HPLC separation measured by online HPLC-ESR coupling technique.

forms a stable adduct with a reactive, short-lived radical. The highly reactive compounds analysed here are inherently linked to the aging process in living tissues.

The spectrum in Figure 8 shows, in addition to the hyperfine splitting owing to the nitrogen nucleus (aN), an additional one caused by the hydrogen nucleus in the ^-position to the unpaired electron (aH). This spin trap does not necessarily allow differentiation between radical species so combination of a separation step with the spin trapping reaction could provide this kind of information.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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