3 research outputs found

    Rapid Screening Method for Detecting Ethinyl Estradiol in Natural Water Employing Voltammetry

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    17α-Ethinyl estradiol (EE2), which is used worldwide in the treatment of some cancers and as a contraceptive, is often found in aquatic systems and is considered a pharmaceutically active compound (PhACs) in the environment. Current methods for the determination of this compound, such as chromatography, are expensive and lengthy and require large amounts of toxic organic solvents. In this work, a voltammetric procedure is developed and validated as a screening tool for detecting EE2 in water samples without prior extraction, clean-up, or derivatization steps. Application of the method we elaborate here to EE2 analysis is unprecedented. EE2 detection was carried out using differential pulse adsorptive cathodic stripping voltammetry (DP AdCSV) with a hanging mercury drop electrode (HMDE) in pH 7.0 Britton-Robinson buffer. The electrochemical process of EE2 reduction was investigated by cyclic voltammetry at different scan rates. Electroreduction of the hormone on a mercury electrode exhibited a peak at −1.16±0.02 V versus Ag/AgCl. The experimental parameters were as follows: −0.7 V accumulation potential, 150 s accumulation time, and 60 mV s−1 scan rate. The limit of detection was 0.49 μg L−1 for a preconcentration time of 150 s. Relative standard deviations were less than 13%. The method was applied to the detection of EE2 in water samples with recoveries ranging from 93.7 to 102.5%

    Improving carvacrol bioaccessibility using core–shell carrier-systems under simulated gastrointestinal digestion

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    The impact of encapsulating carvacrol in chitosan-albumin based core–shell nano-carriers (NCs) on its stability and bioaccessibility was determined under simulated digestion conditions. These NCs consisted of chitosan (C) core enclosed by bovine serum albumin (BSA) shell. The mean particle size ranged from 52.4 ± 10 nm to 203 ± 6 nm and zeta-potential from + 21 ± 3.6 to −18 ± 2.7 mV. The size and charge were significantly modified after the protein-shell formation around the polysaccharide-core. Core-shell NCs were more stable, with less aggregation under simulated gastrointestinal conditions than C-NCs, presumably due to greater steric repulsion. Likewise, core–shell NCs were observed relatively more stabilized in the intestinal phase than gastric phase. The bioaccessibility of carvacrol was enhanced significantly when it was encapsulated in the core–shell NCs. These findings imply that C-BSA based core–shell NCs might be an efficient means of encapsulating, protecting and delivering hydrophobic bioactive compounds for applications in functional foods
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