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Quenching and other special effects

المؤلف:  Sue Jickells , Adam Negrusz (Editors)

المصدر:  Clarkes Analytical Forensic Toxicology

الجزء والصفحة:  p413-414

2026-11-10

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Quenching and other special effects

When the fluorescence of a species is attenuated as a result of its reaction with an analyte, the signal decreases. This effect is called quenching and can be used for quantification purposes, primarily for the determination of anions. Quenching can also be an unwanted effect in the case of dissolved oxygen.

Also, if the analyte is too concentrated, self-quenching may occur when fluorescing molecules collide and lose their excitation energy by radiationless transfer. The fluorescence versus concentration curve may have a maximum and then actually show a decrease in fluorescent power with increasing concentration. It is imperative in quantitative determinations to be aware of this problem, since a given fluorescent power can correspond to two values of concentration.