No abstract

Nanoparticles (NPs) have been used in a range of products due to their unique properties. Nevertheless, these NPs can cause adverse biological effects and because of that, there is a great concern about the health and environmental risks related to their use. Recently, silver nanoparticles (Ag NPs) have been used in a variety of cytotoxicity and genotoxicity studies, but there are still controversies regarding the association between the size and the toxicity of these particles. Therefore, in this study, we aimed to evaluate the cytotoxicity and genotoxicity of Ag NPs (10 and 100 nm) in two different cell lines, CHO-K1 and CHO-XRS5, by performing cell viability assay (XTT), clonogenic assay, micronucleus test, comet assay, as well as by investigating the cell cycle kinetics using the flow cytometry. Cell cultures were exposed to different concentrations of AgNPs (0.025-5.0 μg/ml) for 24 h. Our results indicated that cytotoxicity and genotoxicity induced by the 100 nm-Ag NPs were greater than those induced by the 10 nm-Ag NPs for both cell lines, which suggests that the exposure to greater size particles (100 nm) can cause more adverse biological effects than the exposure to the smaller ones (10 nm).

No abstract

This work investigates the possibility of obtaining isotopic information via the monitoring of the absorption spectra of a gaseous diatomic molecule generated in a graphite furnace and using a high-resolution (approx. 1.5 pm per pixel) monochromator (HR CS GFMAS). To test this concept, Cl was chosen as analyte and AlCl as the target species. The results demonstrate that, unlike what occurs with atomic spectra, under optimum conditions it is possible to acquire isotopic information by HR CS GFMAS in a straightforward way, as it is feasible to observe band heads for each Cl isotope (actually, for Al 35 Cl and Al 37 Cl) that are separated, i.e., they act like two different molecules absorbing at different wavelengths.The method proposed, based upon addition of both Pd and Al and the selection of peak height values, enables Cl isotopic analysis with precision values around 2% RSD for solutions with Cl contents at the mg L -1 level. Accurate values, within this uncertainty, can be directly obtained without requiring any method for mass bias correction. The potential of 2 isotope dilution for calibration is also explored, and it is proven how this approach can help in providing accurate results in situations where the occurrence of chemical interferences, a case frequently encountered for the HR CS GFMAS technique, hampers the use of other calibration approaches, as demonstrated for water analysis.