Enhancement and inhibition of luminol chemiluminescence by phenolic acids

Abstract

We explored the behaviour of a series of phenolic acids used as enhancers or inhibitors of luminol chemiluminescence by three different methods to determine if behaviour was associated with phenolic acid structure and redox character. All the phenolic acids inhibited chemiluminescence when hexacyanoferrate (III) was reacted with the phenolic acids before adding luminol. The redox character of these compounds was clearly related to structure. When hexacyanoferrate(III)-luminol-O2 chemiluminescence was initiated by phenolic acid-luminol mixtures some phenolic acids behaved as enhancers of chemiluminescence, and others as inhibitors. We propose a mechanism to explain these findings. We found direct relationships between the redox character of the phenolic acids and the enhancement or inhibition of the chemiluminescence of the luminol-H2O2-peroxidase system and we propose mechanism to explain these phenomena.

Automated determination of asulam by enhanced chemiluminescence using luminol/peroxidase system

“…[9] Also the CL of the system enhanced by 4-iodophenol was applied to hydrogen peroxide determination. [10,11] In several instances the analyte acts as inhibitor of the reference reaction, producing a decreasing in the speed of the CL reaction. [1] This situation can be used to develop analytical methodologies to determine low concentrations of the inhibitor based on CL inhibition kinetic.…”

Chemiluminescent Detection with Horseradish Peroxidase and Luminol

“…The mechanism is very complex and still under discussion (Diaz et al, 1995). The results of the enhanced luminollHRP reaction strongly depend on the reaction conditions: pH, relative luminol/enhancer concentration, HRP concentration, etc.…”

Selectivity and potential interference from phenolic compounds in chemiluminescence methods for the determination of synephrine

“…Two of the three chemiluminescence reagent systems (luminol and permanganate) have been used to detect a wide range of other compounds, including many with phenolic functionality (16)(17)(18). The reaction of phenolic compounds with cerium(IV) and rhodamine B has been less extensively explored, but Cui and 91 co-workers have recently shown that numerous phenols respond to a closely related reagent system consisting of cerium(IV) and rhodamine 6G (19).…”