Porphyrin Pigment in Black-Lip Pearls and Its Application to Pearl Identification

Abstract

To elucidate the substance which causes fluorescence in black-lip pearl, the substance was extracted from black-lip pearls with 2N-HCl. After being fractionated by talc column chromatography, the substance was converted to methyl ester. Using uroporphyrin I octamethyl ester as a standard, the esterified substance was compared in terms of visible absorption spectra, fluorescence emission spectra, and high performance liquid chromatographic behaviors. Considerable similarities in absorption peaks, fluorescence peak, and retention time resulted between the esterified substance and the standard. From these results the substance was proved to be uroporphyrin I. The experimental result of the existence of porphyrin facilitates percent pearl identification. © 1994, The Japanese Society of Fisheries Science. All rights reserved.