优质淡水珍珠的体色及其与拉曼光谱的关系

RESEARCH ON RELATIONSHIP BETWEEN COLOR AND RAMAN SPECTRUM OF FRESHWATER CULTURED PEARL OF GOOD QUALITY

对不同颜色的优质淡水养殖珍珠进行激光拉曼光谱的研究,并试图从中找出珍珠颜色与其中的有机物以及和拉曼光谱的关系。结果发现,和纯白色系列优质珠相比,粉红色系列优质珠多了1134和1526 cm-1两个峰;紫色系列优质珠中的1017,1295,2231,2609 cm-1在纯白色珍珠和粉红色系列中均未曾出现;在有色珍珠中探测到某有机物的拉曼峰:由C—C伸缩振动引起的1121,1134 cm-1及C=C伸缩振动引起的1503,1526 cm-1,推测此有机物为聚乙炔类物质,不同于以前的研究者所认为的类胡萝卜素。不同色系的珍珠,其拉曼光谱有着明显的区别;随着同色系颜色的加深,有机物拉曼谱峰的强度也越来越强。

Raman spectral study was conducted of freshwater cultured pearls of good quality with different colors. It is expected to find the relationship between colors, organic substance of pearls and their Raman spectra. Tne conclusions were drawn as follows：the wavenumbers, 1134 and 1526 cm^-1,only appeared in the Raman spectra of red pearls, compared with the Raman spectra of white pearls; the Raman shifts which were found in the Raman spectra of violet pearls, 1017,1295, 2231 and 2609 cm^-1, disappeared in the Raman spectra of white and red pearls; the Raman shifts of certain organic compounds, 1121,1134 cm^-1 of C-C wavenumbers and 1503, 1526 cm^-1 of C = C wavenumbers, appeared in colored pearls and the organic substance was considered as pelyacetylenic materials but not carotenoids, as proposed by previous researchers. Pearls of different colors obviously vary with Raman spectrum. The more deeply the same color becomes, the stronger the Raman spectrum of organic substance will be.