Quantitative FT-IR Analysis for Chondritic Meteorites: Search for C_60 in Meteorites

Abstract

Infrared absorption spectra of 9 bulk samples and 3 acid residues of meteorites were obtained in the mid-infrared region (4000 ~ 400 cm^(-1)). From the known composition of meteorites studied, the possible absorption modes were investigated. Most bands of bulk samples occur in the region below 1200 cm^(-1) and they are due to metallic oxides and silicates. The spectra of each group can be distinguished by its own characteristic bands. Acid residues show very distinct features from their bulk samples, and absorption bands due to organic compounds are not evident in their spectra. Quantitative analyses for two carbonaceous (Allende CV3 and Murchison CM2) and one ordinary (Carraweena L3.9) chondrites were performed for the presence of fullerene (C_60) in the meteorites. We calculated the concentration of C_60 in the acid residues by curvefitting the spectra with Gaussian functions. The upper limit of C_60 concentration in these meteorites appears to be less than an order of a few hundred ppm.