Single-Particle ICP-MS/MS Application for Routine Screening of Nanoparticles Present in Powder-Based Facial Cosmetics

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.

Ambient Pressure Ir@Hal-Catalyzed Hydrogenation of Aryl Aldehydes, Ketones, and Phenol

A reliable method for encapsulation of iridium nanoparticles (6-8 nm particles) in halloysite Ir@Hal has been developed. The Ir@Hal nanocomposite was found to be a highly efficient catalyst for the hydrogenation and transfer hydrogenation of the carbonyl group of aryl aldehydes, aryl ketones, and aliphatic ketones to afford alcohols in high yields. In addition, phenol could be hydrogenated to furnish cyclohexanol (93-95% yield) at ambient pressure at 50 °C. Further, the catalyst was easily recovered and recycled without significant loss of catalytic activity over multiple trials.

Halloysite-Catalyzed Esterification of Bio-Mass Derived Acids

Halloysite, a natural clay with a hollow tubular structure, was studied as a catalyst for the esterification of biomass-derived carboxylic acids (levulinic acid, fumaric acid, maleic acid, and succinic acid) with four different alcohols (MeOH, EtOH, n-PrOH, and n-BuOH). Reaction conditions were optimized (10 mol % halloysite, 170 °C, 24 h) and gave high yields of the corresponding esters and diesters (>90%). The halloysite was easily recovered and recycled after washing and drying.