Analysis and characterisation of fullerene nanoparticles

Abstract

Fullerenes or Buckyballs are a group of carbon nanoparticles, classified as engineered nanoparticles. The advent of fullerene nanoparticles in commercial, industrial and biomedical applications raises concern about their potential ecological and human health risks. Fullerenes have not been regulated, although the European Commission (European Commission, 2002), the European Parliament (European Parliament, 2008) and the US Environmental Protection Agency (EPA, 2015) have prioritised legislation on nanomaterials handling and disposal. Given the current lack of studies regarding their presence, fate and behaviour in consumer products and environmental matrices and their associated human and environmental risks it is becoming increasingly important to be able to characterise and quantitate fullerene nanoparticles, especially derivatives, in a wide range of matrix types. To fill these knowledge gaps, one of the objectives of this thesis was the development of analytical methodologies for the determination of pristine and surface modified fullerenes by ultra-high performance liquid chromatography coupled to MS (UHPLC-MS) and by nonaqueous capillary electrophoresis (NACE) and micellar electrokinetic capillary chromatography (MECC) with UV-Vis detection in different environmental matrices (water and sediment samples) and cosmetic products, respectively. In addition, in this thesis the size and shape characterisation of surface modified fullerenes in aqueous solutions of different pH and ionic strength values was studied by combining several techniques (CE, AF4-MALS and TEM). Regarding the analysis of fullerenes, the use of a sub-2 µm C18 column, toluene-methanol as a mobile phase and of APPI ionisation source allowed to develop a UHPLC method coupled to MS/(MS) for the analysis of five pristine (C60-C84) and three surface modified fullerenes (PCBM, PCBB and C60-pyrr) in less than 4.5 min showing high sensitivity and selectivity. Furthermore, the employment of H-SIM mode for pristine fullerenes (mass resolving power ...