Abstract: In this paper, the fluorescence properties of laccaic acid A and the factors affecting them were investigated. In order to develop a new method to detect laccaic acid A, its metal ion recognition capacity was evaluated. The results showed that the chemical properties and polarity of the solvent used to laccaic acid A, concentration and pH on affected the fluorescence intensity and emission wavelength of laccaic acid A. Cu2+, Fe3+, Fe2+, and Pb2+ quenched the fluorescence intensity of laccaic acid A, while Zn2+ and Al3+ led to fluorescence enhancement. Notably, Al3+ showed significant specificity. Other metal ions had little effect on the fluorescence intensity. In the presence of Al3+ (0.04 mol/L), the fluorescence intensity of laccaic acid A was linear with its concentration. The application results showed that laccaic acid A could be detected in two different beverages by a fluorescence method with Al3+ as the standard solution. The recovery rates of the method were between 95.0% and 109.3%, with relative standard deviations (RSDs) in the range of 1.9% to 5.4%. This new method has great potential for practical application.

Key words: laccaic acid A, fluorescence, metal ion, detection method