*3.1.3 Fourier-transform infrared (FTIR) spectroscopy*

FTIR is useful to acquire an infrared spectrum of a solid sample either feed or product. In FTIR spectroscopy, most molecules absorb light in the infra-red region of the electromagnetic spectrum and this absorption corresponds to the specific bonds present in the molecule. Measurement usually is in wave numbers typically over the range 4000–400 cm<sup>1</sup> . When the sample being analysed is exposed to radiation, some portion of the radiation is absorbed while other is transmitted. The block diagram of the FTIR spectrometer is shown in **Figure 9**. Dunite and carbonated products were analysed by FTIR (Bruker, Tensor 37 Spectrometer). Samples for FTIR spectroscopy were prepared using 99% KBr and 1% sample. Samples were thoroughly mixed and ground before making pellets. These pellets were placed in an oven under a vacuum at 150°C for 24 hours before analysis. Typical FTIR spectra of raw dunite are provided in **Figure 10**.
