Determination of tannic acid based on luminol chemiluminescence catalyzed by cupric oxide nanoparticles

In this study, it was found that tannic acid could inhibit the chemiluminescence (CL) intensity of luminol–H2O2–cupric oxide nanoparticles significantly. Based on this inhibition effect, a novel and highly sensitive flow injection method with inhibited chemiluminescence was developed for the determination of tannic acid. Under optimum conditions, the net CL intensity was proportional to the concentration of tannic acid over the range of 10–100 nM and the detection limit was 2.6 nM. The relative standard deviation (RSD) for six repeated determinations of 80 nM tannic acid was 2.8%. Note that this method has been successfully used for the analysis of tannic acid in real Chinese gall samples.