Testing the resistance of fullerenes to chemothermal oxidation used to isolate soots from environmental samples

We tested the resistance of five different fullerenes (C60, C70, C76/78 mix, and C84) to chemothermal oxidation at 375 °C (CTO-375), a method that has been used and tested for quantifying black carbon (BC) and CNTs in soils and sediments. C60 survived CTO-375 the most (50%), while C70 was the fullerene with the lowest survival rate (<1%). Standard additions of C60 to soil and sediment reference materials yielded recoveries between 18 and 36%. Although lower than recoveries previously observed for soot and CNTs, these results demonstrate the capability of CTO-375 to partially isolate C60 from solid environmental matrices. Standard additions of C70, C76/78, and C84 yielded slightly higher survival rates when added to soil and sediment than in their pure form. These results indicate that the mineral matrices of these samples probably had a catalytic effect towards C60 and a protective effect towards C70, C76/78, and C84 during CTO-375.

► C60, C70, C76/78 mix, and C84 were subjected to CTO-375. ► Pure C60 partly survived CTO-375, whereas the other fullerenes largely did not. ► CTO-375 partially isolated C60 fullerenes from soils and sediments. ► Carbonaceous material quantified in previous studies using CTO-375 may include C60.