生物成因文石的FTIR光谱特征

对13种文石质软体动物贝壳的内外壳层进行了较系统的FTIR光谱测量，并重点对文石的ν₁，ν₂及ν₄3个内振动模式的频率与贝壳壳层位置的关系进行了分析。结果表明，文石的ν₁，ν₄带在所有的样品中未存在频率位移现象，且与合成文石的相关谱带的频率一致，但ν₂带频率与贝壳壳层的位置有密切关系。在同一生物种类贝壳中，所有样品内壳层文石的ν₂带频率均大于外壳层。随贝壳种类的不同，内外壳层ν₂带频率位移的范围为0.5～4.5 cm-1。关于文石质贝壳内外壳层红外光谱中ν₂带存在频率位移的现象是首次报道。

Characteristics of FTIR Spectra of Biogenic Aragonite in Mollusk Shells

The FTIR spectra of aragonites in outer and inner layers of thirteen species of mollusk shells were systematically measured, and the frequency variations of v1, v2 and v4 bands of the aragonites with the positions of shell layers were analyzed. The results showed that the frequency of v2 band differed in different species of shells and the positions of shell layers, but the frequendes of the other two bands were not altered, and had the same values with synthetic aragonites. In the same species of shells, the frequency of v2 band in inner layers was greater than that in outer layers, and the frequency shift of v2 band between inner and outer layers was in the range of 0.5-4.5 cm^-1 in all studied samples. The detection of frequency shift of v2 band in different layers of aragonitic mollusk shell was first reported in this paper.