No abstract

The rotating disk sorptive extraction (RDSE) technique was applied in this study to the extraction of 16 polycyclic aromatic hydrocarbons (PAHs) in real water samples. The sorptive and desorptive behavior of the analytes were studied by using a rotating disk coated with polydimethylsiloxane (PDMS) on one of its surfaces. The optimal conditions for extractions of all analytes were: rotational velocity of the disk: 1250 rpm; sample volume: 20 mL; matrix modifier: 20 % MeOH and extraction time: 30 min. A desorption time of 10 min at 1250 rpm was used for the analytes using 5 mL of methanol. PAHs were measured in the extract by gas chromatography coupled to mass spectrometry (GC-MS). Under these conditions, recoveries ranging from 84 to 100 % were obtained in drinking water enriched with the analytes, and the precision, expressed as relative standard deviation, was between 2 and 20%. The detection limit of the method was between 8 and 115 ng L -1 depending on the analyte. The method was applied to the analysis of water samples obtained from a lagoon in Curauma, Chile, obtaining quantitative recoveries.

Purpose Triclosan (TCS, 5-chloro-2-(2,4-dichlorophenoxy) phenol) an antimicrobial compound used in a range of household products, is an emerging hydrophobic organic contaminant, that may be incorporated into soil through the application of biosolids. The present study assessed the bioavailable fraction of TCS in a soil-biosolid system using wheat (Triticum aestivum) plant assays and a predictive extraction method using a solution of hydroxypropyl-beta-cyclodextrin (HPCD) to determine if it was a reliable surrogate for this bioassay. Materials and methods Three soils were obtained from the central region of Chile (Cuesta Vieja, Polpaico, and Taqueral). Biosolid was obtained from a regional wastewater treatment plant. The soils were amended with biosolids at different rates (30, 60, 90, and 200 Mg ha(-1)). The TCS concentration was determined in biosolids, soil, and plant samples via gas chromatography coupled with mass spectrometry (GC-MS). Results and discussion The total TCS concentration in the biosolids was 5.45 mg kg(-1). The results of the TCS extraction from the wheat plants (roots and shoots) indicated that TCS was primarily found in the roots. TCS uptake by the plant varied based on soil properties. The predictive capability of the HPCD extraction was assessed using a simple linear correlation test for TCS concentration in wheat plants. Conclusions The study yielded a linear relationship, which demonstrated the validity of the chemical method as a biosimulation technique.FONDECYT 1110115 110008