No abstract

Due to their antifungal, antibacterial, antiviral, and antimicrobial properties, silver nanoparticles (AgNPs) are used in consumer products intended for use by children or in the home. Children may be especially affected by the normal use of consumer products because of their physiological functions, developmental stage, and activities and behaviors. Despite much research to date, children’s potential exposures to AgNPs are not well characterized. Our objectives were to characterize selected consumer products containing AgNPs and to use the data to estimate a child’s potential non-dietary ingestion exposure. We identified and cataloged 165 consumer products claiming to contain AgNPs that may be used by or near children or found in the home. Nineteen products (textile, liquid, plastic) were selected for further analysis. We developed a tiered analytical approach to determine silver content, form (particulate or ionic), size, morphology, agglomeration state, and composition. Silver was detected in all products except one sippy cup body. Among products in a given category, silver mass contributions were highly variable and not always uniformly distributed within products, highlighting the need to sample multiple areas of a product. Electron microscopy confirmed the presence of AgNPs. Using this data, a child’s potential non-dietary ingestion exposure to AgNPs when drinking milk formula from a sippy cup is 1.53 μg Ag/kg. Additional research is needed to understand the number and types of consumer products containing silver and the concentrations of silver in these products in order to more accurately predict children’s potential aggregate and cumulative exposures to AgNPs.

Quercetin is a naturally occurring flavonoid that is known to form complexes with metals; a process that reduces the environmental availability of toxic metals such as chromium. We hereby report the first evidence of the removal of Cr(VI) fromenvironmental samples using quercetin (QCR) and two synthetic derivatives: namely quercetin pentaphosphate (QPP) and quercetin sulfonic acid (QSA). We successfully synthesized both QPP andQSA using simple procedures while characterizing them with UV-vis spectroscopy, H1-NMR,13C NMR,31P-NMR, and LC-MS techniques. The solubility of QPP was found to be 840 mg/mL and aqueous solutions of both QPP and QSA were stable for over a period of 1 year. Quercetin and these derivatives were subsequently utilized for the reduction of Cr(VI) and QCR was found to have a higher reduction efficiency of 99.8% (30 min), followed by QPP/palladium nanoparticles mixture (PdNPs) at 96.5% (60 min), and finally QSA/PdNPs mixtures at 91.7% (60 min). PdNPs catalyst increased the efficiency by∼36.5% while a change in operating temperature from 25 to 45°C improved the efficiency by∼46.8%. Electron paramagnetic resonance spectroscopy was used to confirm the presence of Cr (III) in the reaction products. This reduction approach was validated in environmental (Binghamton University) BU and standard reference material (BRS)soil samples. Results showed that the analysis could be completed within one hour and the efficiency was higher in BU soil than in BRS soil by 16.1%. QPP registered the highest % atom economy of 94.6%. This indicates enhanced performance compared tobio remediation approach that requires several months to achieve about 90% reduction efficiency.

Flavonoids constitute a large family of plant-derived polyphenolic compounds that are found in fruits, vegetables, spices, wines and juices 1. Examples of flavonoids include quercetin, fisetin, luteolin, apeginin, myricetin and many others. Previous studies have shown that these compounds exhibit an array of biological effects that are beneficial to humans, including antiviral, antioxidative, anti-inflammatory and anticarcinogenic. The solubility of these polyphenolic compounds can be increased through the modification of the chemical structure, which may improve oral bioavailability 2. As a result, considerable efforts have been directed towards the development of novel, highly soluble conjugates having clinical profiles that are similar or even superior to those exhibited by the parent molecules in vitro. These include synthetic esters, acyl