Citation: | Luwei Fan, Mingxing Yang. In Situ Resonance Raman Spectra of Organic Pigments in Momo Coral. Journal of Earth Science, 2008, 19(2): 146-151. |
In this study, Raman scattering measurements were obtained for momo corals covering their typical range of colors. Three different excitation wavelengths (785, 633, 514 nm) are used for the same samples at the same points. All the samples show the two major Raman features of polyenic compounds assigned to double carbon-carbon (C=C) stretching vibration at approximately 1 500 cm-1 and single carbon-carbon (C—C) stretching vibration at approximately 1 130 cm-1 bond stretching mode. These peaks are not detected in the corresponding white parts of momo corals. However, some changes in intensities, shape, and position of C=C stretching vibrations of the same point are observed by using different excitation wavelengths. The exact position of C—C stretching vibration of polyenic molecules depends strongly on the number of double bonds contained in their polyenic chain. In addition, the number of double bonds contained in the polyenic chains shows that different colors of the red momo coral are caused by different mixtures of polyenic compounds.
Barnard, W., De Waal, D., 2006. Raman Investigation of Pigmentary Molecules in the Molluscan Biogenic Matrix. Journal of Raman Spectroscopy, 37: 342 doi: 10.1002/jrs.1461 |
Kaczorowska, B., Hacura, A., Kupka, T., et al., 2003. A Spectroscopic Characterization of Natural Coral. Analytical and Bioanalytical Chemistry, 377(6): 1032–1037 doi: 10.1007/s00216-003-2153-1 |
Karampelas, S., Fritsch, E., Mevellec, J. Y., et al., 2007. Determination by Raman Scattering of the Nature of Pigments in Cultured Freshwater Pearls from the Mollusk Hyriopsis Cumingi. Journal of Raman Spectroscopy, 38: 217–230 doi: 10.1002/jrs.1626 |
Merlin, J. C., 1985. Resonance Raman Spectroscopy of Carotenoids and Carotenoid-Containing System. Pure and Applied Chemistry, 57: 758–792 |
Merlin, J. C., Delé, M. L., 1983. Etude par Spectroscopie Raman de Resonance de la Pigmentation des Sequelettes Calcaires de Certains Coreaux. Bulletin de la Société Zoologique de France, 108: 289–301 |
Merlin, J. C., Delé-Dubios, M. L., 1986. Resonance Raman Characterization of Polyacetylenic Pigments in the Calcareous Skeleton. Comparative Biochemistry and Physiology, 84B(1): 97 doi: 10.1016/0300-9629(86)90048-4 |
Okamoto, H., Saito, S., Tasumi, M., et al., 1984. Resonance Raman Spectra and Excitation Profiles of Tetradesmethyl-ß-Carotene. Journal of Raman Spectroscopy, 15: 331–335 doi: 10.1002/jrs.1250150508 |
Rolandi, V., Brajkovic, A., Adamo, I., et al., 2005. Gem Corals: Classification and Spectroscopic Features. Australian Gemmologist, 22(7): 285–297 |
Schaffer, H., Chance, R., Silbey, R., et al., 1991. Conjugation Length Dependence of Raman Scattering in a Series of Linear Polyenes: Implications for Polyacetylene. Journal of Chemistry and Physics, 94: 4161–4170 doi: 10.1063/1.460649 |
Schügerl, F. B., Kuzmany, H., 1981. Optical Modes of Trans-polyacetylene. Journal of Chemistry and Physics, 74: 953 doi: 10.1063/1.441151 |
Stradi, R., Pini, E., Celentano, G., 2001. Carotenoids in Bird Plumage: The Complement of Red Pigments in the Plumage of Wild and Captive Bullfinch (Pyrrhula pyrrhula). Comparative Biochemistry and Physiology, 128B: 529–535 doi: 10.1016/S1096-4959(00)00353-5 |
Veronelli, M., Zerbi, G., Stradi, R., 1995. In Situ Resonance Raman Spectra of Carotenoids in Bird's Feathers. Journal of Raman Spectroscopy, 26: 683–692 doi: 10.1002/jrs.1250260815 |
Zou, R. L., Gan, Z. J., Chen, S. M., et al., 1993. Red Coral. Science Press, Beijing (in Chinese) |