Polymeric and silica sorbents on endocrine disruptors determination

Abstract

A B S T R A C TEndocrine disrupting determination at low concentration levels comprises one of the most important targets in environmental analytical chemistry. In spite of inherent high sensitivities obtained for HPLC, these techniques have some limitations depending on the contaminants. As a result, interest in preconcentration using solid-phase extraction (SPE) still continues increasingly for endocrine disrupting determinations by HPLC due to the high accuracy of this method. In this work, we evaluated three different adsorbents in preconcentration of endocrine disruptors in three different categories: pharmaceuticals (sulphamethoxazole, trimethoprim and diclofenac), hormones (estrone, 17β-estradiolacetate and 17β-estradiol) and plastic materials (bisphenol A) in multicomponent aqueous solution using the combination SPE -HPLC. The adsorbents investigated were such as modified silica (octadecylsilane)-DSC-18 (Supelco) and two polymers, a divinylbenzene-N-vinilpirolidona -Oasis ® HLB (Waters) and a styrene-divinylbenzene modified with butyrolactone-Strata-X™ (Phenomenex). The parameters selected to evaluate the best adsorbent were sample loaded, breakthrough volume, recovery and adsorption capacity. The results showed that the polymeric sorbents Oasis and Strata presented good separation and selective ability, then the most efficient sorbent for the described test was applied to the determination of endocrine disruptor (ED) in a wastewater real sample. Almost all endocrine disruptors studied in the present work were found and quantified in the effluent sample, suggesting the selected cartridge could be useful for preconcentration technique of endocrine disruptors in environmental analytical applications. Correlation analysis identified the adsorption parameters which had the most influence in efficiency of SPE adsorbents, such as initial ED concentration, breakthrough volume and recovery.

Reactive Adsorption of Parabens on Synthesized Micro- and Mesoporous Silica from Coal Fly Ash: pH Effect on the Modification Process

“…At pH 3, the adsorption capacity was higher; thus, this pH was chosen for the later studies. At pH values 5 and 7 (values generally found in surface water), − the material presented the adsorptive capacity approximate to the results identified at pH 3, indicating no relevant interference of this parameter in the studied range, which would facilitate the application of the adsorbent for resolving practical environmental problems.…”

Enhanced removal of emerging micropollutants by applying microaeration to an anaerobic reactor

“…according to Vidal et al (2015). The biogas was characterized in terms of air (O 2 + N 2 ), CH 4 , and CO 2 by gas chromatography with thermal conductivity detection (GC-TCD) (GC-17A, Shimadzu Corporation, Japan) according to Firmino et al (2015).…”

“…There are biological and non-biological processes (physical, chemical, and physicochemical) for removing these compounds from environmental water matrices. The non-biological methods include advanced oxidation processes, ozonation, nanofiltration, reverse osmosis, and adsorption on zeolite or activated carbon (DE LA CRUZ et al, 2012;VIDAL et al, 2015). However, these techniques incur high installation and operational costs.…”

Tecnologias Digitais e Aprendizagem Docente

“…A coleta dos dados ocorreu por meio de entrevistas com 10 docentes de instituições públicas e privadas situadas em diferentes estados brasileiros. Os autores concluem que as tecnologias digitais também aparecem em ambiente virtual de aprendizagem (AVA), e-book, educação híbrida, grupo digital, mundos digitais virtuais 3D, metodologias ativas, curso on-line aberto e massivo (MOOC), plataformas adaptativas, docências e tecnologias móveis (Vidal;Mercado, 2020).…”