Browsing by Author "Gomez, Marisol"

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    Detection of SO2 derivatives using a new chalco-coumarin derivative in cationic micellar media: application to real samples
    (2018) Gomez, Marisol; Aliaga Miranda, Margarita Elly; Arancibia Moya, Verónica; Moya, Alexis; Segura, Camilo; Nunez, Marco T.; Aguirre, Pabla; Nagles Vidal, Edgar Orlando; Garcia-Beltran, Olimpo
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    Determination of a natural (17β-estradiol) and a synthetic (17α-ethinylestradiol) hormones in pharmaceutical formulations and urine by adsorptive stripping voltammetry
    (2019) Jose Trivino, Juan; Gomez, Marisol; Valenzuela, Javiera; Vera, Ariesny; Arancibia, Veronica
    An efficient, fast and sensitive method for the determination of 17 beta-estradiol, (E2) and 17 alpha-ethinylestradiol (EE2) in pharmaceutical formulations and in urine was developed and validated using a hanging mercury drop electrode (HMDE), screen printed carbon electrodes (SPCE), and screen printed carbon nanotube electrodes (SPCNTE). Both analyzes are adsorbed on the working electrodes. To obtain sensitive and selective methods, the effects of various parameters such as pH, adsorption potential, and time (E-ads, t(ads)) were optimized. The optimum experimental conditions chosen for the two analyzes were pH: 10.0; E-ads: - 0.60 and t(ads): 30 s, when HMDE was used. Under these conditions, one reduction signal was found at -1.31 V for E2 and two reduction signals at - 0.23 V and -1.20 V for EE2. The detection limits (DLs) were found to be 0.3 mu g L-1 for E2, 14.8 mu g L-1 for EE2 at - 0.23 V, and 9.7 mu g L-1 for EE2 at -1.20 V. On the other hand, in screen printed electrodes E2 and EE2 present oxidation of the phenolic hydroxyl groups at 0.30, 0.31, 0.32, and 0.33 V (pH:10) with DLs of 242, 277; 182, and 191 mu g L-1 for SPCE and SPCNTE, respectively. The method was successfully applied to the determination of these analyzes in Primaquin (R) (E2), Gynera (R) (EE2), spiked urine (with EE2), and urine samples of women who used Tinelle (R) (EE2) as contraceptive drug.
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    Determination of Se(IV) concentration via cathodic stripping voltammetry in the presence of Cu(II) ions and ammonium diethyl dithiophosphate
    (2019) Merino, Ignacio E.; Stegmann, Edgardo; Aliaga Miranda, Margarita Elly; Gomez, Marisol; Arancibia Moya, Verónica
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    Ex situ prepared nafion-coated antimony film electrode for adsorptive stripping voltammetry of model metal ions in the presence of pyrogallol red
    (2013) Arancibia, Veronica; Nagles, Edgar; Rojas, Carlos; Gomez, Marisol
    A nafion-coated antimony film electrode (NSbFE) was prepared ex situ and applied to the model metal ions Pb(II) and Cd(II) by adsorptive stripping voltammetry in the presence of pyrogallol red (PGR). To enhance the electroanalytical performance of the NSbFE, we optimized several operational parameters, including antimony concentration, deposition potential and time used in the preparation of the electrode, and effect of pH, ligand concentration (C-PGR), adsorptive potential, and time (E-ads, t(ads)). The NSbFE exhibited well developed signals for the reduction of the adsorbed complexes at -0.63 and -0.92 V for Pb-PGR and Cd-PGR, respectively, with higher current compared to unmodified electrodes. The optimum parameters for NSbFE preparation consisting of 100 mg L-1 Sb(III), 0.5 mol L-1 HCl at -1.5 V (150 s) and for the determination of Pb(II) and Cd(II) were pH = 4.5 (acetate buffer); C-PGR = 2.8 mu mol L-1; E-ads = -0.40 V and t(ads) = 100 s. The electrode presents good linear behavior in the examined concentration range from 0.9 to 12.0 mu g L-1 for both metal ions, with a limit of detection (3 sigma) of 0.4 and 0.9 mu g L-1 for Pb(II) and 0.5 and 1.0 mu g L-1 for Cd(II) using 2-mm and 3-mm diameter glassy carbon electrodes, respectively. The relative standard deviation for a Pb(II) a Cd(II) solution (9.8 mu g L-1) was 2.0% for six successive assays. The method was validated using certified reference water for trace elements (TMDA-61) with satisfactory results. Finally, the method was applied to the determination of Pb(II) and Cd(II) in tap and mineral water. (C) 2013 Elsevier B.V. All rights reserved.
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    Limitations and opportunities for the appropriation of the Mediterranean diet in Chilean adults with diagnostic elements of metabolic syndrome
    (2024) Calderon, Maribel; Plaza, Gianella; Gomez, Marisol; Samith, Barbara; Pinto, Victoria; Martinez, Ximena; Sara, Daniela; Echeverria, Guadalupe; Calzada, Mariana; Berkowitz, Loni; von Schultzendorf, Andrea; Pedrals, Nuria; Bitran, Marcela; Rigotti, Attilio
    Background: a healthy food intake pattern, specifically the Mediterranean diet (MedDiet), is a factor associated with reduced risk, lower prevalence, and better management of chronic diseases. However, there is limited information regarding how patients integrate proposals for adherence to this food pattern in their daily lives. Objective: to identify factors and conditions that influence adherence to the MedDiet in Chile. Methods: an exploratory qualitative study was applied in 35 to 65 -year -old patients of both sexes who presented at least one diagnostic criterion of metabolic syndrome (MetS). Through in-depth interviews and focal groups, knowledge, assessment, attitudes, and practices associated with changes and maintenance of healthy eating habits, with emphasis on the MedDiet, were investigated. Information analysis was carried out under the grounded theory approach using the ATLAS.ti software. Results: participants recognized the value of healthy eating, including the MedDiet, but declared low knowledge (identification of single foods items) together with facilitators (variety of ingredients) and limiting factors (taste, availability/cost of some items, family dynamics) for its routine adoption. In addition, change in eating habits generates a high initial cognitive and emotional load that requires not only individual but also relational effort as it implies modifications of family and collective practices. Conclusions: information obtained on barriers and opportunities to adhere to healthy eating such as the MedDiet is key to design and implement nutritional interventions based on this food pattern and that can be sustainable in time for chronic disease management in Chile.
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    New fluorescent turn-off probes for highly sensitive and selective detection of SO2 derivatives in a micellar media
    (2017) Gomez, Marisol; Pérez Hernández, Edwin Gregorio; Arancibia Moya, Verónica; Iribarren, Constanza ; Bravo Díaz, Carlos; García Beltrán, Olimpo; Aliaga Miranda, Margarita Elly
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    Simultaneous Determination of Antimony(III) and Molybdenum(VI) by Adsorptive Stripping Voltammetry Using Quercetin as Complexing Agent
    (2013) Rojas, Carlos; Arancibia, Veronica; Gomez, Marisol; Nagles, Edgar
    A sensitive and selective voltammetric method for simultaneous determination of Sb(III) and Mo(VI) using Quercetin (Q) as complexing agent is described. Optimal conditions were found to be: pH3.7, CQ=6.0 mu molL1 and Eacc=0.10V. The LOD (3 sigma) for Sb(III) are 0.076 and 0.040 mu gL1, whereas for Mo(VI) are 0.086 and 0.048 mu gL1 with tacc of 60 and 120s, respectively. The method was validated using synthetic sea water (ASTM D665) and was applied to the determination of Sb(III) and Mo(VI) in natural waters with satisfactory results.
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    Willingness to mitigate climate change: the role of knowledge, trust, and engagement
    (2024) Larrain, Antonia; Freire, Paulina; Cofre, Hernan; Andaur, Ana; Tolppanen, Sakari; Kang, Jingoo; Grez, Joaquin; Gomez, Marisol; Vergara, Claudia; Rojas, Maria Teresa; Arenas, Andoni
    The recent IPCC report (IPCC, 2023) highlighted the need to increase the perception of risk and prompt climate action through education. The question is what contribution science and environmental education can make-if any-to this challenge. Psychological research has suggested that knowledge (topical and epistemological) and beliefs about self-efficacy are relevant starting points, but the evidence is scarce and inconsistent. We conducted a transversal correlational study to test the direct and indirect effects of system knowledge of climate change, personal engagement with science, and trust in climate science on the willingness to mitigate the effects of climate change. The participants were 386 students attending high schools in Chile. The results reveal that there is no direct effect of climate change system knowledge on the willingness to act. We did find indirect effects of system knowledge on the willingness to act, mediated by personal engagement with science and trust in climate science knowledge. The results also demonstrate a direct effect of personal engagement with science, and an indirect effect mediated by trust in science. The implications for science education are discussed.