有机显微组分的二次离子质谱研究

采用二次离子质谱技术（ＳＩＭＳ）对煤及源岩中不同成熟度的镜质体、丝质体、沥青和笔石进行了详细研究。结果表明不同显微组分具有不同的ＳＩＭＳ谱图，反映出其化学组成和结构的差异性，且ＣＨ２＾＋／ＣＨ３＾＋参数变化趋势可以用来评价有机组分的热演化规律。同时说明ＳＩＭＳ技术是有机显微组分化学成分和结构研究的有效手段。

STUDY OF MACERALS IN HYDROCARBON SOURCE ROCKS BY SECONDARY ION MASS SPECTROMETRY

SIMS (secondary ion mass spectrometry) technique is used for the study of vitrinite, fusinite, bitumen and graptolite in the hydrocarbon source rocks with different maturities It is found that different macerals have different SIMS spectra, which reflects the differences in chemical composition and structure of macerals And with increases in thermal evolution degree, the m/z moves to high mass numbers, spectral peaks becomes small in number Graptolite is poorer in aromatics than vitrinite, so graptolite is relatively good oil source materials The mass numbers 218,219,234,248,249 occur in graptolite and bitumen, but absent in vitrinite, which indicates that there exists thiophene sulphur in the former The change trend of parameter CH + 2/CH + 3 shows: graptolite is more sensitive to heat in high maturity stage, the reflectance can be used as a thermal indicator; vitrinite is moderately sensitive to heat, the reflectance is a suitable thermal indicator from low to high maturity stage; the bitumen reflectance can be used as a maturity indicator from low to mature stage The study results demonstrate that the SIMS technique is a powerful means for studying in situ the chemical composition and structure of macerals