Abstract
We report the first use of NiO, Fe(3)O(4), TiO(2), and Co(3)O(4) nanoparticles as surfaces for surface-assisted laser desorption/ionization (SALDI) mass spectrometry of asphaltenes. Higher signal-to-noise ratios (S/Ns) for asphaltene species were observed using NiO and Fe(3)O(4) nanoparticles for SALDI as compared to LDI, where both surfaces consistently provided 2- to 3-fold improved S/Ns. The new SALDI detection method showed reliable adsorption data measuring supernatant solutions after 24 hour asphaltene adsorption on NiO, Fe(3)O(4), and Co(3)O(4). These results indicated that NiO has a higher adsorption affinity than Fe(3)O(4) and Co(3)O(4) for asphaltene molecules, corroborating reported asphaltene adsorption on metal oxide nanoparticles.