Person: Madrid Albarrán, María Yolanda
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First Name
María Yolanda
Last Name
Madrid Albarrán
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Química Analítica
Area
Química Analítica
Identifiers
7 results
Search Results
Now showing 1 - 7 of 7
Item Determination of phenolic compounds in residual brewing yeast using matrix solid-phase dispersion extraction assisted by titanium dioxide nanoparticles(Journal of Chromatography A, 2019) Gómez Mejía, Esther; Rosales Conrado, Noelia; León González, María Eugenia De; Madrid Albarrán, María Yolanda; ELSEVIERA simple and efficient low-cost matrix solid-phase dispersion (MSPD) extraction based on TiO2nanopar-ticles (NPs) and diatomaceous earth has been developed for the recovery of phenolic compounds fromresidual brewing yeast. Experimental conditions for MSPD extraction were optimized by an experimen-tal design approach. A screening factorial design plus replicates at the center point, followed by surfaceresponse analysis were used. The simultaneous identification and quantification of eleven main nat-ural polyphenols: caffeic, chlorogenic, p-coumaric, 3,4-dihydroxibenzoic, trans-ferulic and gallic acids,kaempferol, myricetin, naringin, quercetin and rutin, was possible by combining MSPD and capillaryliquid chromatography couple to a diode array detection system (cLC-DAD) and liquid chromatogra-phy couple to a triple quadrupole analyzer (LC–MS/MS). Moreover, residual brewing yeast extracts wereevaluated in terms of DPPH (1,1-diphenyl–2 picrylhydrazyl) free radical scavenging activity. Polyphenol-nanoparticle interaction was studied by UV–vis spectroscopy and electron transmission microscopy(TEM), pointing out a stable interplay that assists phenolic isolation. The extracted polyphenol quan-tities were within the 3.2-1,500 g g−1range, and the high antioxidant activity estimated suggested thatdeveloped MSPD is a successful, simple, efficient and rapid method for the extraction and recovery of bioactive phenolic compounds, which promotes the reuse and re-evaluation of brewing yeast agri-foodby-products.Item Simultaneous determination of the size and concentration of AgNPs in water samples by UV–vis spectrophotometry and chemometrics tools(Talanta, 2018) Moreno Martín, Gustavo; León González, María Eugenia De; Madrid Albarrán, María YolandaThe combination of UV–vis spectrophotometry with a chemometric calibration tool based on partial least squares (PLS) has allowed us the development of a multivariate analytical method that simultaneously estimates the concentration and size of mixtures of silver nanoparticles (AgNPs) in environmental water samples. The method is based on changes in the surface plasmon resonance band (SPRB) of AgNPs when they form aggregated/assembled structures with L-cysteine (L-cys). Measurementts were performed by employed a fixed-time kinetics method that implies that the final spectra (response) are obtained by subtstracting the solutions spectra at fixed times. Optimization of experimental conditions affecting aggregation such as time, temperature, pH and concentration of aggregating substance was performed by experimental design and response surface methodologies (RSM). A multivariate calibration model using AgNPs of known diameter size ((20 ± 3), (41 ± 3), (59 ± 5) and (79 ± 7) nm) within a concentration range between 0.62 and 2.5 mg L−1 was constructed by using a mixture experimental design and PLS. The method was finally applied to estimate size and concentration of AgNPs in AgNPs-spiked river and tap water samples. Water samples were spiked with individual, binary and ternary mixtures of AgNPs of different sizes and by using two types of AgNPs: citrate-coated AgNPs (cit-AgNPs) and polyvinylpyrrolidone-coated AgNPs (PVP-AgNPs). A good correspondence was obtained between predicted values and the total amount of AgNPs added with recovery values ranged within 80–160% for the individual mixtures, 68–108% for the binary mixtures and 60–64% for the ternary mixtures of AgNPs. Finally, transmission electron microscopy (TEM) measurements were performed for those cases where discrepancies between the expected and the obtained values were observed. TEM micrographs evidenced the presence of agglomerates or aggregates of AgNPs in some of the mixtures or water tested.Item Simultaneous determination of the size and concentration of AgNPs in water samples by UV–vis spectrophotometry and chemometrics tools(Talanta, 2018) Moreno Martín, Gustavo; León González, María Eugenia De; Madrid Albarrán, María YolandaThe combination of UV–vis spectrophotometry with a chemometric calibration tool based on partial least squares (PLS) has allowed us the development of a multivariate analytical method that simultaneously estimates the concentration and size of mixtures of silver nanoparticles (AgNPs) in environmental water samples. The method is based on changes in the surface plasmon resonance band (SPRB) of AgNPs when they form aggregated/assembled structures with L-cysteine (L-cys). Measurementts were performed by employed a fixed-time kinetics method that implies that the final spectra (response) are obtained by subtstracting the solutions spectra at fixed times. Optimization of experimental conditions affecting aggregation such as time, temperature, pH and concentration of aggregating substance was performed by experimental design and response surface methodologies (RSM). A multivariate calibration model using AgNPs of known diameter size ((20 ± 3), (41 ± 3), (59 ± 5) and (79 ± 7) nm) within a concentration range between 0.62 and 2.5 mg L−1 was constructed by using a mixture experimental design and PLS. The method was finally applied to estimate size and concentration of AgNPs in AgNPs-spiked river and tap water samples. Water samples were spiked with individual, binary and ternary mixtures of AgNPs of different sizes and by using two types of AgNPs: citrate-coated AgNPs (cit-AgNPs) and polyvinylpyrrolidone-coated AgNPs (PVP-AgNPs). A good correspondence was obtained between predicted values and the total amount of AgNPs added with recovery values ranged within 80–160% for the individual mixtures, 68–108% for the binary mixtures and 60–64% for the ternary mixtures of AgNPs. Finally, transmission electron microscopy (TEM) measurements were performed for those cases where discrepancies between the expected and the obtained values were observed. TEM micrographs evidenced the presence of agglomerates or aggregates of AgNPs in some of the mixtures or water tested.Item In-vivo solid phase microextraction for quantitative analysis of volatile organoselenium compounds in plants(Analytica Chimica Acta, 2019) Moreno Martín, Gustavo; Sanz Landaluce, Jon; León González, María Eugenia De; Madrid Albarrán, María Yolanda; ElsevierA new calibration method based on the use of headspace solid-phase microextraction (HS-SPME) and in-fiber internal standardization, combined with gas chromatography coupled to mass spectrometry (GC/MS) was developed for quantifying Se volatile organic species released by plants exposed to chitosan-modified selenium nanoparticles (Cs-SeNPs). The effect of several parameters affecting extraction and separation of the selected organic species of selenium (dimethylselenium (DMSe), diethylselenium (DESe) and dimethyldiselenium (DMDSe)) and deuterated dimethyl sulphide (d6-DMS) employed as internal standard were studied and optimized using an experimental design. The developed methodology was applied for quantifying the volatile selenium compounds produced over time by the plant species Raphanus sativus and Brassica juncea grown in hydroponic solution containing 5 mg Se L−1 in the form Cs-SeNPs. The procedure employed consisted in two steps. Volatile selenium species released from the plants were first extracted in the SPME fiber located at the headspace of a box with a fixed volume. Subsequently, the internal standard placed in a vial subjected to the same conditions as plants was extracted on the same fiber than the one previously used for extracting selenium compounds. Finally the extracted compounds were separated and analyzed by GC/MS. Results evidenced Cs-SeNPs biotransformation into DMSe and DMDSe by both plants species during growing stage, in amounts of the order of ng. Additionally, the resulting data were submitted to multifactorial ANOVA to evaluate the influence of plant type and time of exposure to Cs-SeNPs on the production of volatile selenium compounds.Item Residual brewing yeast as a source of polyphenols: Extraction, identification and quantification by chromatographic and chemometric tools(Food Chemistry, 2018) León González, María Eugenia De; Gómez Mejía, Esther; Rosales Conrado, Noelia; Madrid Albarrán, María YolandaA method combining aqueous extraction, reversed-phase high-performance capillary liquid chromatography with photodiode array detection (cLC-DAD) and chemometric tools, was developed to determine phenolic compounds in residual brewing yeast. The effect of temperature, nature of extraction solvent and method for separation of extract solution were studied to optimize the extraction conditions on the basis of total phenolic content (TPC), total flavonoids content (TFC) and antioxidant capacity. Polyphenols were determined by cLC-DAD. Flavonols as rutin and kaempferol, flavonoids as naringin, phenolic acids as gallic acid and antioxidants as trans-ferulic and p-coumaric acids were found and quantified in the brewing residue. Data were subjected to evaluation using multifactor ANOVA and principal component analysis (PCA), both showing that lyophilization pretreatment affects the content of individual polyphenols and that residual brewing yeast contains higher polyphenol amounts than the liquid beer waste. The obtained results suggest that residual brewing yeast could be a source of polyphenols.Item Extraction, identification and quantification of polyphenols from spent coffee grounds by chromatographic methods and chemometric analyses(Waste Management , 2019) Ramón-Gonçalves, Marina; Gómez Mejía, Esther; Rosales Conrado, Noelia; León González, María Eugenia De; Madrid Albarrán, María YolandaA solid-liquid extraction method using ethanol-water mixtures was combined with cLC-DAD, LC-MS/MS and chemometric analyses for establishing the optimum extraction conditions of valuable polyphenols from spent coffee grounds. Chlorogenic and p-coumaric acids were the most abundant polyphenols found, ranging from 0.02 to 4.8 mg g−1 and 0.173–0.50 mg g−1, respectively. In addition, total polyphenol content (9–29 mg GAE g−1 DW), total flavonoid content (11–27 mg QE g−1 DW), total antioxidant activity (0.3–7 mg GAE g−1 DW) and free radical scavenging ability (DPPH assay, 64–927 µg extract g−1 at EC50) of obtained extracts were determined. Response surface methodology allowed obtaining predictive models for the extraction of each individual polyphenol. On the other hand, multifactorial ANOVA was used to establish differences between coffee and spent coffee ground extracts. Principal component analysis was also employed to relate antioxidant activities, total polyphenol and total flavonoid contents with both the polyphenols extracted and the residue coffee type. The overall results suggested that spent coffee grounds could be reused as a promising, inexpensive and natural source of bioactive polyphenols with potential industrial applications, thus minimizing the waste disposal and environmental impact.Item Citrus peels waste as a source of value-added compounds: Extraction and quantification of bioactive polyphenols(FOOD CHEMISTRY, 2019) Gómez Mejía, Esther; Rosales Conrado, Noelia; León González, María Eugenia De; Madrid Albarrán, María YolandaA method combining solid-liquid extraction based on ethanolic aqueous solution, cLC-DAD and chemometrics, was performed to extract and quantify polyphenols from citrus peels. LC-MS/MS was also employed for chemical profiling. The effect of extraction variables on the recovery was examined by experimental factorial design. Data were evaluated using multifactorial-ANOVA, response surface analysis and Principal Component Analysis. trans-Ferulic and p-coumaric antioxidants were found in lower quantities (<1.4 mg·g−1) in all peel extracts. Narangin flavonoid was also identified in all samples, while rutin flavonol was determined in the concentration range of 3.3–4.7 mg·g−1. The most abundant polyphenol in the extracts obtained from all evaluated citrus samples was the flavanone hesperidin (280–673 mg·g−1). Furthermore, peel extracts were evaluated in terms of total polyphenol and flavonoid content, total antioxidant activity and DPPH free radical scavenging. The obtained results suggested that evaluated citrus peel by-products could be reused as a source of polyphenols and transformed into value-added products.