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The characterization of nanoparticles (NPs) in hydrocarbon matrices using single particle inductively coupled plasma mass spectrometry (spICP-MS) is underdeveloped. There are less than ten publications using spICP-MS in hydrocarbon matrices, and none have applied the technique to determine NP concentration and size distribution in asphaltenes after in-situ upgrading of heavy oils via solvent deasphalting. To our knowledge, no studies have used spICP-MS to track the nature of NP additives in the asphaltene fraction in hydrocarbons without adulteration of the sample. Particle number concentrations (PNC) derived from spICP-MS in hydrocarbon matrices are reported for the first time. Fe2O3 PNC increased by an order of magnitude, and NiO PNC increased 28 % compared to samples without additives, indicating that NPs were reasonably well-dispersed in the asphaltenes. Ionic concentrations were higher for Ni than Fe, which showed negligible changes in all samples. Here, we report the lowest size detection limits recorded for Fe2O3 NPs (32 nm ± 1 nm) using spICP-MS in hydrocarbon matrices. Further, NiO and Fe2O3 NP sizes matched the initial sizes added to the oil before precipitation, providing evidence that the nature of the NPs does not change after deasphaltation and subsequent mixing with asphaltenes. This study expands our understanding of the interactions between metal NPs and asphaltenes when used as co-precipitants during in situ upgrading of heavy crude oil. 

The short- and long-term impacts of nanoparticles (NPs) in consumer products are not fully understood. Current European Union (EU) regulations enforce transparency on products containing NPs in cosmetic formulations; however, those set by the U.S. Food and Drug Administration are lacking. This study demonstrates the potential of single-particle inductively coupled plasma tandem mass spectrometry (spICP-MS/MS) as a screening method for NPs present in powder-based facial cosmetics (herein referred to as FCs). A proposed spICP-MS/MS method is presented along with recommended criteria to confirm particle presence and particle detection thresholds in seven FCs. FC products of varying colors, market values, and applications were analyzed for the presence of Bi, Cr, Mg, Mn, Pb, Sn, Ag, Al, and Zn NPs based on their ingredient lists as well as those commonly used in cosmetic formulations. The presence of NPs smaller than 100 nm was observed in all FC samples, and no correlations with their presence and market value were observed. Here, we report qualitative and semi-quantitative results for seven FC samples ranging in color, brand, and shimmer. 

Rare earth elements (REEs) make up a group of unique elements with diverse applications in energy, medicine, and technology. Increasing global demand and limited supplies have led to exploring the economic viability of domestic feedstock extraction from sources such as coal. Little is known about the release of REEs from coal due to the environmentally driven processes of photodissolution. In this study, the photodissolution of water-soluble REEs and dissolved organic carbon (DOC) from subbituminous coal was investigated using laboratory-simulated sunlight exposures. The effects of the solar intensity, temperature, and exposure time on photodissolution were also examined. Following irradiation, water-soluble REE and DOC concentrations increased significantly above nonirradiated controls, indicating photodissolution is a significant process. Both solar intensity and exposure time influenced photodissolution rates, while temperature did not. Results from this study provide motivation to further investigate the photodissolution pathways of REEs from subbituminous coal and interaction with DOC ligands, given that photosolubilized REEs may be organic associated. These findings may have implications, both positive and negative, for the environmental impact of REEs.