Figure 2

FTIR spectra of milky fluid, granules, calcite and vaterite. a) Finger print region (2000–650 cm⁻¹) of the FTIR spectra for a typical crushed granule and the milky fluid, together with spectra for reference synthetic ACC [46], synthetic calcite , calcite (Coblentz society spectrum No. 4659) and synthetic vaterite spectra. The milky fluid and Coblentz society spectrum No. 4659 were used in the component regression carried out on the μ-FTIR spectra. Samples are offset on the vertical axis for clarity. b) FTIR spectra between 4000 and 650 cm⁻¹ for the milky fluid and a typical granule showing the lipid peaks and the water peaks at high wavenumbers (see text). Samples are offset on the vertical axis for clarity.