Photodegradation of methanol, glutamic acid and glucose on the surface of iron-bearing minerals

Here we present preliminary results for the degradation of glutamic acid and the stabilisation of glucose on the surfaces of olivine [(FexMg1-x)2 SiO4] and haematite [Fe2O3]. The concentration of glutamic acid and glucose was determined by UV-Vis spectroscopy. It was found that the concentration of glutamic acid decreased from 43.73 mg L-1 to 28.90 mg L-1 in the presence of olivine and from 42.53 mg L-1 to 30.11 mg L-1 in the presence of haematite, after irradiation of the solutions for 96 hours with UV light [wavelength (WV)=254 nm]. A smaller decrease was observed when the solutions were irradiated with UV light of wavelength WV=365 nm. On the other hand, the concentration of glucose in remained stable during irradiation in the presence of haematite. It was decreased slightly in the presence of olivine and significantly in the control solution that contained no minerals. Concentration of the organics in the solutions that were kept in the dark remained stable during the experiments.