Fish scale foil is used as a natural food colorant. As the commercially available product is a suspended argent liquid, we analyzed the solvent and the particles, respectively. In result, the solvent was identified as ethanol by HS-GC/MS, and the suspended particles were confirmed by PDA-LC/MS to be mainly three purine derivatives, namely guanin, hypoxanthine, and xanthine. Their concentrations were 79.38%, 1.64% and 2.01% in the particles, respectively, by the absolute curves of the standards.
