Novo método para determinação de poluentes orgânicos persistentes (POPs) em água usando DI-SPME-GC/MS e estudo de remediação com eficientes nanomateriais

Abstract

The monitoring of persistent organic pollutants (POPs) is a very important topic on research in environmental chemistry for the search of a new analytical methods that allows advances and improvements in their identification and quantification in different matrix, as well as inthe search for new remediation methodologies and materials with good cost-effective improvement. POPs monitoring needs to be effectively implemented in accordance with the Stockholm Convention and it is the Convention participants who should contribute to these globalmonitoring mechanisms to obtain comparable data on the presence of these pollutants, identify changes in their concentrations over time, and provide information on environmental transport. This work presents the development of a new direct immersion solid-phase microextractionmethod (DI-SPME) for the simultaneous analysis of persistent organic pollutants (POPs), specifically the pesticide endosulfan, and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) present at trace levels in water samples. No previous studies related to the simultaneouslyextraction of these compounds through SPME have been reported, which demonstrates the relevance of this work. Identification and quantification was performed by gas chromatography coupled to mass spectrometry (GC/MS). The method was optimized through factorial planning of four variables 24. The method was validated based on the recommendations given by Eurachem (2014) and showed limits of quantification (LOQs) for and endosulfan of 916,0 and 126,0 ng L-1 respectively, and 10.0 ng L-1 for 2,3,7,8-TCDD. Another goal of this study was the review of POPs situation in Latin America, especially in Brazil and Mexico. We searched the institutions and regulations in charge and applied in bothcountries for the regulation of pesticides such as endosulfan and the inventory and regulation of polychlorodibenzo-p-dioxins such as 2,3,7,8-TCDD. The maximum permissible limits (MPLs) of the regulated compounds and the most recent inventories by each country arepresented. The method developed was applied to real samples of superficial water, collected in the water channels of Xochimilco, Mexico City, Mexico and collected at Pampulha Lagoon, Belo Horizonte, Brazil.Finally, the results of the study of remediation of these pollutants in aqueous samples with different adsorption materials (carbon nanotubes, modified bentonite and modified vermiculite) are presented, and the efficiency of each material discussed.