Little is known regarding the use and ambient levels of pesticides in Chilean agricultural regions. Chlorpyrifos (CPF) is one of the most used active ingredients in Chile and in the world. However, few investigations have been conducted to understand its environmental distribution and fate. In this study, PUF disk passive air samples were deployed during ∼one year in two areas, Angol (5 sites) and Villarrica (2 sites), in the Araucanía Region. The concentration in air of CPF ranged from ten to thousands of pg m−3 (∼20–14 600). The highest CPF concentrations were detected at the Angol sites (∼14 600 pg m3) during period 2 (August–December 2008). These results were higher by a factor of ∼10–15 than those detected in Villarica sites (∼2000 pg m3) in period 1 (April–July 2008). Seasonal CPF variations were observed, at both sites, within the sampling periods. Air back trajectory analyses showed that air masses from nearby agricultural zones contributed most of the CPF detected in Angol sites when the wind speed was low and at Villarrica when those sources were likely located north of the VMA site. These results provide initial data for CPF in the Chilean atmosphere and contribute new information to understanding distribution of CPF in Chilean environments

Indexación: Web of Science; Scopus.Nanoparticles (NPs) of new fluoride (SrF2 and MgF2) nanocompounds were synthesized by the simple chemical method of precipitation in ethanol. Synthesis of the strontium fluoride (SrF2)-magnesium oxide (MgO) nanocomposite was achieved through the ultrasonic method. These prepared nanopowders were characterized through Fourier transform infrared (FT-IR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, Powder X-ray Diffraction (PXRD) and Scanning Electron Microscopy (SEM). FT-IR confirmed the purity of the synthesized fluoride NPs by evaluation of the vibrations, and UV-Visible showed the intense absorption peaks of NPs. PXRD analysis indicated the average of particle size, and SEM demonstrated a nearly spherical morphology of the NPs. The antibacterical properties of the nanopowders on Staphylococcus Aureus, Bacillus Subtilis and E. Aklay bacteria were studied, with the strongest effect by the magnesium fluoride (MgF2) NPs and the SrF2-MgO nanocomposite.http://ref.scielo.org/yfr3f

A new amlodipine-chitosan nanocomposite was built using amlodipine nanoparticles as primary scaffolds by spontaneous emulsification, and its complete elucidation was performed by using several spectrometric techniques. Our results indicate that the amlodipine-chitosan nanocomposite has better solubility than amlodipine at pH 7.4 with a nearly all the drug substance dissolved (97%) by the final time-point measured. The docking study support the existence of intermolecular interactions are established between amlodipine and chitosan.