23 results on '"Nuria Rodríguez Fariñas"'
Search Results
2. Electrical asymmetric-flow field-flow fractionation with a multi-detector array platform for the characterization of metallic nanoparticles with different coatings
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Sergio Fernández-Trujillo, Armando Sánchez-Cachero, Francisco Javier Guzmán Bernardo, Nuria Rodríguez-Fariñas, María Jiménez-Moreno, and Rosa Carmen Rodríguez Martín-Doimeadios
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Biochemistry ,Analytical Chemistry - Abstract
Electrical asymmetric-flow field-flow fractionation (EAF4) is a new and interesting analytical technique recently proposed for the characterization of metallic nanoparticles (NPs). It has the potential to simultaneously provide relevant information about size and electrical parameters, such as electrophoretic mobility (μ) and zeta-potential (ζ), of individual NP populations in an online instrumental setup with an array of detectors. However, several chemical and instrumental conditions involved in this technique are definitely influential, and only few applications have been proposed until now. In the present work, an EAF4 system has been used with different detectors, ultraviolet-visible (UV-vis), multi-angle light scattering (MALS), and inductively coupled plasma with triple quadrupole mass spectrometry (ICP-TQ-MS) for the characterization of gold, silver, and platinum NPs with both citrate and phosphate coatings. The behavior of NPs has been studied in terms of retention time and signal intensity under both positive and negative current with results depending on the coating. Carrier composition, particularly ionic strength, was found to be critical to achieve satisfactory recoveries and a reliable measurement of electrical parameters. Dynamic light scattering (DLS) has been used as a comparative technique for these parameters. The NovaChem surfactant mix (0.01%) showed a quantitative recovery (93 ± 1%) of the membrane, but the carrier had to be modified by increasing the ionic strength with 200 μM of Na
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- 2023
3. Quantitative analysis and characterization of PtNPs in road dust based on ultrasonic probe assisted extraction and single particle inductively coupled plasma mass spectrometry
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Armando Sánchez-Cachero, Nuria Rodríguez Fariñas, María Jiménez-Moreno, and Rosa Carmen Rodríguez Martín-Doimeadios
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Instrumentation ,Spectroscopy ,Atomic and Molecular Physics, and Optics ,Analytical Chemistry - Published
- 2023
4. Assessment by a multi-technique approach of PtNPs' transformations in waters under relevant environmental concentrations and conditions
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Armando, Sánchez-Cachero, Nuria Rodríguez, Fariñas, Ángel, Ríos, and Rosa Del Carmen Rodríguez, Martín-Doimeadios
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Environmental Engineering ,Environmental Chemistry ,Pollution ,Waste Management and Disposal - Abstract
Once released to the environment, platinum nanoparticles (PtNPs) can undergo different transformations and are affected by several environmental conditions. An only analytical technique cannot provide all the information required to understand those complex processes, so new analytical developments are demanded. In the present work, the potential of asymmetric flow field flow fractionation hyphenated to inductively coupled plasma mass spectrometry (AF4-ICP-MS) for these studies, has been investigated, and classical dynamic and electrophoretic light scattering (DLSELS) have been used as complementary techniques. The role of ionic strength, ionic water composition, and natural organic matter (NOM) in the behaviour of PtNPs of different sizes (5 and 50 nm) has been specifically studied. Dynamic and electrophoretic light scattering have been used to track changes in the hydrodynamic diameters (d
- Published
- 2023
5. AF4-ICP-MS as a powerful tool for the separation of gold nanorods and nanospheres
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Sara López-Sanz, Nuria Rodríguez Fariñas, Mohammed Zougagh, R.C. Rodríguez Martín-Doimeadios, and Ángel Ríos
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Materials science ,Resolution (mass spectrometry) ,Elution ,010401 analytical chemistry ,Analytical chemistry ,Regenerated cellulose ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Analytical Chemistry ,Asymmetric flow field flow fractionation ,Transmission electron microscopy ,Nanorod ,Absorption (chemistry) ,0210 nano-technology ,Inductively coupled plasma mass spectrometry ,Spectroscopy - Abstract
An analytical methodology based on asymmetric flow field flow fractionation (AF4) hyphenated to inductively coupled plasma mass spectrometry (ICP-MS) has been developed to separate gold nanorods (AuNRs) and nanospheres (AuNSs). This separation is of special interest because the latter are the main impurity in the synthesis of AuNRs by seeding growth procedures, and quality control tools are highly demanded. AF4-ICP-MS separation was performed using a regenerated cellulose membrane (molecular weight cut-off, MWCO, of 10 kDa), a 350 μm thick spacer and a phosphate buffer (1 mM NaH2PO4, 1 mM Na2HPO4 at pH 7) with 0.01% SDS as carrier. Several experimental parameters, such as focusing conditions and elution cross flow, and the injection/focusing time were optimized. Working under the optimum separation conditions, an adequate resolution was achieved between the void peak, commercially available AuNSs and AuNRs. The optimized method was successfully applied to the analysis of the products obtained in the synthesis procedure for AuNRs of 4.6 aspect ratio. Absorption molecular spectroscopy and transmission electron microscopy (TEM) have been used as complementary techniques.
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- 2020
6. Assessment by a Multi-Technique Approach of Ptnps’ Transformations in Waters Under Relevant Environmental Concentrations and Conditions
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Rosa Carmen Rodríguez Martín-Doimeadios, Armando Sánchez-Cachero, Nuria Rodríguez Fariñas, María Jiménez-Moreno, and Ángel Ríos
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- 2022
7. Temporal variability measurements of PM
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Ana, Rodríguez, Susana, Seseña, Enrique, Sánchez, María, Rodríguez, M Llanos, Palop, Rosa Del Carmen, Rodríguez Martín-Doimeadios, and Nuria, Rodríguez Fariñas
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Air Pollutants ,Africa, Northern ,Atmosphere ,Humans ,Dust ,Particulate Matter ,Seasons ,Environmental Monitoring - Abstract
A novel and multidisciplinary observational analysis of atmospheric components in the Central Iberian Peninsula is presented here. PM
- Published
- 2020
8. A method based on asymmetric flow field flow fractionation hyphenated to inductively coupled plasma mass spectrometry for the monitoring of platinum nanoparticles in water samples
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Armando Sánchez-Cachero, Sara López-Sanz, Ángel Ríos, R.C. Rodríguez Martín-Doimeadios, and Nuria Rodríguez Fariñas
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chemistry.chemical_classification ,Chromatography ,Natural water ,010401 analytical chemistry ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Platinum nanoparticles ,01 natural sciences ,0104 chemical sciences ,Analytical Chemistry ,Asymmetric flow field flow fractionation ,Membrane ,chemistry ,Critical parameter ,Analytical strategy ,Humic acid ,0210 nano-technology ,Inductively coupled plasma mass spectrometry - Abstract
An analytical methodology based on asymmetric flow field flow fractionation hyphenated to inductively coupled plasma mass spectrometry (AF4-ICP-MS) has been developed for monitoring citrate coated platinum nanoparticles (PtNPs) of different sizes (5, 30, and 50 nm) in water samples. Several factors have been optimized, such as carrier composition, AF4 separation program, focusing step or cross flow values. Under the optimum conditions, PtNPs can be fractionated in about 30 min in a single run with quantitative recoveries of the membrane (100 ± 7%, n = 5). The optimized method has been successfully applied to study transformations, not only in size but also surface modifications, of PtNPs in synthetic and natural water samples over time. The effect of organic matter was specifically studied, and it was found to be a critical parameter. The analytical strategy followed in this work can be very useful to develop further environmental studies involving PtNPs.
- Published
- 2020
9. Speciation of platinum nanoparticles in different cell culture media by HPLC-ICP-TQ-MS and complementary techniques: A contribution to toxicological assays
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Sergio Fernández-Trujillo, R.C. Rodríguez Martín-Doimeadios, Nuria Rodríguez-Fariñas, and María Jiménez-Moreno
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Chromatography ,Chemistry ,Cell Culture Techniques ,Metal Nanoparticles ,Nanoparticle ,Context (language use) ,Protein Corona ,Reversed-phase chromatography ,Mass spectrometry ,Platinum nanoparticles ,Biochemistry ,Analytical Chemistry ,Dynamic light scattering ,Environmental Chemistry ,Biological Assay ,Inductively coupled plasma mass spectrometry ,Chromatography, High Pressure Liquid ,Spectroscopy ,Platinum - Abstract
Toxicological studies of nanoparticles (NPs) are highly demanded nowadays but they are very challenging. In the in vitro assays, the understanding of the role of cell culture media is crucial to derive a proper interpretation of the toxicological results and to do so, new analytical tools are necessary. In this context, an analytical strategy based on reversed-phase liquid chromatography hyphenated to inductively coupled plasma-triple quadrupole mass spectrometry (HPLC-ICP-TQ-MS) has been developed for the first time for the detection and characterization of both 5 and 30 nm PtNPs, as well as ionic platinum species, in commonly used cell culture media. For this purpose, Dulbecco's Modified Eagle Medium, DMEM-high glucose, DMEM-F12, DMEM 31053–028, and Roswell Park Memorial Institute, RPMI-1640 (supplemented with 10% fetal bovine serum (FBS) and antibiotics) at several incubation times (24, 48, and 96 h at 37 °C) were tested. After a careful optimization and analytical performance, the developed method allows to simultaneously study the oxidation process, leading to the release of ionic species, and the increase in the hydrodynamic volume of PtNPs, probably related to the formation of new biological entities (protein corona). The magnitude of both processes was found to be dependent on the tested cell culture media and incubation times. Dynamic light scattering (DLS) and high-resolution scanning electron microscopy (HR-SEM) were used as complementary techniques to study the important process of both soft and hard protein corona formation. The feasibility of the HPLC-ICP-TQ-MS to get relevant information for toxicological studies has been demonstrated and in light of our results, the influence of the cell culture media on the behavior of PtNPs should not be underestimated.
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- 2021
10. Geno- and cytotoxicity induced on Cyprinus carpio by aluminum, iron, mercury and mixture thereof
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Youssef Paolo Mendoza-Zenil, R.C. Rodríguez Martín-Doimeadios, Nuria Rodríguez-Fariñas, Ricardo Pérez-Pastén Borja, Armando Elizalde-Velázquez, Hariz Islas-Flores, Leobardo Manuel Gómez-Oliván, Marcela Galar-Martínez, Sandra García-Medina, Nely SanJuan-Reyes, and Ninfa Ramírez-Durán
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0301 basic medicine ,Carps ,Iron ,Health, Toxicology and Mutagenesis ,chemistry.chemical_element ,010501 environmental sciences ,medicine.disease_cause ,01 natural sciences ,Cyprinus ,Industrial wastewater treatment ,03 medical and health sciences ,Common carp ,medicine ,Animals ,Cytotoxicity ,0105 earth and related environmental sciences ,Micronucleus Tests ,biology ,Caspase 3 ,Public Health, Environmental and Occupational Health ,Mercury ,General Medicine ,biology.organism_classification ,Pollution ,Mercury (element) ,Comet assay ,030104 developmental biology ,chemistry ,Environmental chemistry ,Micronucleus test ,Comet Assay ,Biomarkers ,Water Pollutants, Chemical ,Genotoxicity ,Aluminum ,DNA Damage - Abstract
Metals such as Al, Fe and Hg are used in diverse anthropogenic activities. Their presence in water bodies is due mainly to domestic, agricultural and industrial wastewater discharges and constitutes a hazard for the organisms inhabiting these environments. The present study aimed to evaluate geno- and cytotoxicity induced by Al, Fe, Hg and the mixture of these metals on blood of the common carp Cyprinus carpio. Specimens were exposed to the permissible limits in water for human use and consumption according to the pertinent official Mexican norm [official Mexican norm NOM-127-SSA1-1994] Al (0.2mgL-1), Fe (0.3mgL-1), Hg (0.001mgL-1) and their mixture for 12, 24, 48, 72 and 96h. Biomarkers of genotoxicity (comet assay and micronucleus test) and cytotoxicity (caspase-3 activity and TUNEL assay) were evaluated. Significant increases relative to the control group (p
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- 2017
11. Screening-confirmation strategy for nanomaterials involving spectroscopic analytical techniques and its application to the control of silver nanoparticles in pastry samples
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Francisco Javier Guzmán Bernardo, Nuria Rodríguez Fariñas, Ana I. Corps Ricardo, R.C. Rodríguez Martín-Doimeadios, and Ángel Ríos
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Silver ,Metal Nanoparticles ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Mass Spectrometry ,Silver nanoparticle ,Analytical Chemistry ,Nanomaterials ,law.invention ,Luminol ,chemistry.chemical_compound ,law ,Particle Size ,Instrumentation ,Inductively coupled plasma mass spectrometry ,Spectroscopy ,Reliability (statistics) ,Chemiluminescence ,Detection limit ,Chemistry ,Reproducibility of Results ,021001 nanoscience & nanotechnology ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Asymmetric flow field flow fractionation ,0210 nano-technology - Abstract
The full characterization of nanomaterials (NMs), which requires a range of different and expensive equipment, is not always necessary to meet certain demands of information. Qualitative analytical methods are ideal alternatives when only a piece of information is required. In this work, a qualitative method for the screening of NMs has been developed and statistically validated for the first time, with silver nanoparticles (AgNPs) as a proof of concept. It is based on the generation of chemiluminescence of the luminol/Ag+ system in alkaline media in the presence of AgNPs. Measurements are obtained in a short time with a simple instrument. Probability of detection (POD) curves were constructed at three cut-off values next to the limit of detection of the chemiluminescent method. The unreliability region (UR) was from 0.50 to 1.82 μg L−1. Currently, no regulation on AgNPs exists, but the present method was successfully tested for a hypothetical threshold of 2.5 μg L−1 of 40 nm AgNPs. The method was applied to silver colored pearls, with silver (E-174) or aluminum (E-173) coating, used for decoration of pastry. Performance parameters such as false negative and positive rates as well as specificity, sensitivity and reliability rates were calculated for validation. The results of the screening method were confirmed by asymmetric flow field flow fractionation coupled to inductively coupled plasma mass spectrometry (AF4-ICP-MS). The proposed screening method is simple, fast, economic, and easy to transfer to routine laboratories in the field of food safety.
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- 2021
12. Temporal variability measurements of PM2.5 and its associated metals and microorganisms on a suburban atmosphere in the central Iberian Peninsula
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Susana Seseña, Nuria Rodríguez Fariñas, R.C. Rodríguez Martín-Doimeadios, María Angeles Davia Rodríguez, Enrique Sánchez, Ana M. Rodríguez, and M. Llanos Palop
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Suburban area ,Range (biology) ,Microorganism ,010501 environmental sciences ,Mineral dust ,Atmospheric sciences ,complex mixtures ,01 natural sciences ,Biochemistry ,Natural (archaeology) ,Atmosphere ,03 medical and health sciences ,Intrusion ,0302 clinical medicine ,Peninsula ,Relative humidity ,030212 general & internal medicine ,0105 earth and related environmental sciences ,General Environmental Science ,Trace elements ,geography ,geography.geographical_feature_category ,Airborne microbiot ,Particles ,Environmental chemistry ,Environmental science - Abstract
A novel and multidisciplinary observational analysis of atmospheric components in the Central Iberian Peninsula is presented here. PM2.5 concentrations and both populations of cultivable and non-cultivable microorganisms and concentrations of a wide range of trace elements associated have been simultaneously studied during multiple events along one year. The aim has been to characterize their potential relations and dependencies, and their seasonal, daily and hourly evolution. Tools that could explain the atmospheric mechanisms and sources from all these elements have been also evaluated. As it would be expected from a suburban environment, ab- solute levels obtained were not close to legislation limits. Anthropogenic and natural sources, such as heating home, soil resuspension, or Sahara dust intrusion; and atmospheric factors are responsible for higher PM2.5 and metals concentrations in months with both low and high temperatures. Daily and hourly evolution depends on University Campus activity, especially on traffic flow and resuspended dust due to human transit. No statistical significant differences on daily or seasonal scales between cultivable counts of fungi and bacteria were displayed. However, using the q-PCR technique, the bacterial population was lower in winter. Positive correlations between PM2.5 and relative humidity; and PM2.5 and cultivable microorganism have been established. It was also the case among 7 of the 11 trace elements, indicating then common natural or anthropogenic sources. In summary, this work illustrates the interest of a combined inspection of elements, interactions and dependencies when studying the unique and continuous atmospheric environment, which are typically analysed separately
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- 2020
13. Analytical strategy based on asymmetric flow field flow fractionation hyphenated to ICP-MS and complementary techniques to study gold nanoparticles transformations in cell culture medium
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Nuria Rodríguez Fariñas, Sara López-Sanz, R.C. Rodríguez Martín-Doimeadios, and Ángel Ríos
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Absorption spectroscopy ,Ultrafiltration ,Metal Nanoparticles ,02 engineering and technology ,01 natural sciences ,Biochemistry ,Citric Acid ,Mass Spectrometry ,Analytical Chemistry ,Phosphates ,Environmental Chemistry ,Particle Size ,Inductively coupled plasma mass spectrometry ,Spectroscopy ,Chromatography ,Chemistry ,010401 analytical chemistry ,Regenerated cellulose ,021001 nanoscience & nanotechnology ,Fractionation, Field Flow ,0104 chemical sciences ,Culture Media ,Asymmetric flow field flow fractionation ,Membrane ,Transmission electron microscopy ,Colloidal gold ,Gold ,0210 nano-technology - Abstract
An analytical methodology based on asymmetric flow field flow fractionation (AF4) hyphenated to inductively coupled plasma mass spectrometry (ICP-MS) has been developed to study gold nanoparticles (AuNPs) in cell culture medium (Dulbecco's Modified Eagle Medium, DMEM, containing 10% fetal bovine serum, FBS, and antibiotics) used for in vitro toxicological studies. AF4-ICP-MS separation of AuNPs was performed using a regenerated cellulose membrane (molecular weight cut-off, MWCO, of 10 kDa). The carrier composition and the AF4 separation program were optimized. Under the optimum conditions, AuNPs of different types, i.e. phosphate buffered saline (PBS) and citrate stabilized, and sizes (10, 30 and 40 nm), without and with cell culture medium could be separated. The developed method allowed to detect transformations in AuNPs and dissolved gold species (Au3+) induced by this medium, such as an increase in the hydrodynamic volume and oxidation. Centrifugal ultrafiltration (CU), transmission electron microscopy (TEM) and Ultraviolet–visible (UV–vis) absorption spectrophotometry have been used as complementary techniques to study these processes. This information is of major interest to have a correct interpretation of the in vitro toxicological studies of NPs, which are more and more demanded due to the increasing concerns about the safe use of these materials and their impacts. This work demonstrates the potential of hyphenated techniques based on AF4 to achieve this relevant information.
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- 2018
14. Methodology for monitoring gold nanoparticles and dissolved gold species in culture medium and cells used for nanotoxicity tests by liquid chromatography hyphenated to inductively coupled plasma-mass spectrometry
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Ángel Ríos, R.C. Rodríguez Martín-Doimeadios, Rosario Serrano Vargas, Nuria Rodríguez Fariñas, and Sara López-Sanz
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Plasma Gases ,Metal Nanoparticles ,02 engineering and technology ,Mass spectrometry ,01 natural sciences ,High-performance liquid chromatography ,Mass Spectrometry ,Analytical Chemistry ,HeLa ,Toxicity Tests ,Humans ,Nanotechnology ,Inductively coupled plasma mass spectrometry ,Chromatography, High Pressure Liquid ,Chromatography ,biology ,Chemistry ,010401 analytical chemistry ,Reversed-phase chromatography ,021001 nanoscience & nanotechnology ,biology.organism_classification ,0104 chemical sciences ,Culture Media ,Cell culture ,Colloidal gold ,Nanotoxicology ,Gold ,0210 nano-technology ,HeLa Cells - Abstract
An analytical methodology based on coupling reversed-phase liquid chromatography (HPLC) to an inductively coupled plasma mass spectrometry (ICP-MS) has been developed for the characterization and identification of gold nanoparticles (AuNPs) and gold dissolved species (Au3+) in culture medium (Dulbecco's Modified Eagle Medium, DMEM) and HeLa cells (a human cervical adenocarcinoma cell line) used in nanotoxicity tests. The influence of the culture medium was also studied and the method applied for nanotoxicity tests. It was also observed that AuNPs can undergo an oxidation process in the supernatants and only a small amount of AuNPs and dissolved Au3+ was associated with cells. To evaluate the biological impact of AuNPs, a classical viability assay onto HeLa cells was performed using cellular media DMEM in the presence of increasing dosage of 10nm AuNPs. The results showed that 10nm AuNPs exhibit a slight toxic effect.
- Published
- 2016
15. Multiresidue determination of organochlorines in fish oil by GC–MS: A new strategy in the sample preparation
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Nuria Rodríguez Fariñas, R.C. Rodríguez Martín-Doimeadios, José Antonio Castro Osma, Francisco Javier Guzmán Bernardo, Juan José Berzas Nevado, and José María González Cogolludo
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Detection limit ,Time Factors ,Chromatography ,Chemistry ,Elution ,Pesticide Residues ,Reproducibility of Results ,Food Contamination ,Fractionation ,Chemistry Techniques, Analytical ,Gas Chromatography-Mass Spectrometry ,Analytical Chemistry ,Electron capture detector ,Fish Oils ,Certified reference materials ,Limit of Detection ,Calibration ,Dietary Supplements ,Fatty Acids, Omega-3 ,Hydrocarbons, Chlorinated ,Sample preparation ,Gas chromatography ,Gas chromatography–mass spectrometry ,Food Analysis - Abstract
A rapid, economic and environmentally friendly analytical methodology has been implemented for the determination of alpha-, beta-, gamma- and delta-HCH, p,p'-DDT, p,p'-DDD and p,p'-DDE, PCBs congeners #28, #52, #101, #153, #138 and #180 and Hexachlorobenzene in fish oil. 1,2,3,4-Tetrachloronaphtalene was used as internal standard. The sample preparation, consisting of a single step of clean-up and fractionation, took place in a column filled with different layers of neutral and sulphuric acid modified silica. The analytes were eluted by vacuum with of hexane. Significant reduction in terms of solvents, sorbents, and analysis time was achieved in comparison with literature. Gas chromatography coupled to mass spectrometry was used for the separation and determination of the analytes. The instrumental limits of detection were from 0.1 to 1.3ngmL(-1) and the response of the detector was linear up to 200ngmL(-1). The separation proved to be precise (RSD
- Published
- 2010
16. Development and validation of an analytical methodology for the determination of p,p′-DDT, p,p′-DDE and p,p′-DDD in fish oil pills
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R.C. Rodríguez Martín-Doimeadios, Nuria Rodríguez Fariñas, Juan José Berzas Nevado, and Francisco Javier Guzmán Bernardo
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Vitamin ,Detection limit ,chemistry.chemical_compound ,Electron capture detector ,Analyte ,Chromatography ,chemistry ,Analytical technique ,Cod liver oil ,Gas chromatography ,Fish oil ,Spectroscopy ,Analytical Chemistry - Abstract
An analytical methodology was proposed and validated to be applied to the determination of p , p′ -DDT and its metabolites p , p′ -DDE and p , p′ -DDD in fish oil. The analytical procedure presented in this paper involves a single-step clean up process prior to the analysis. A solution of 1,2,3,4-tetrachloronaphtalene was used as internal standard. The analytical technique used was gas chromatography coupled to an electron capture detector. Details on the validation process are provided. The limits of detection ranged from 2.6 to 4.7 pg μL − 1 . The BCR 598 standard reference material (cod liver oil) was used to evaluate the performance of the methodology with satisfactory recoveries for all the compounds. The analytes were determined in three different fish oil pills sold in Spain as a supplementary vitamin support. The sum of p , p′ -DDT and metabolites was from 13.2 to 51.3 ng g − 1 , the dominant compound being p , p′ -DDE.
- Published
- 2007
17. Analysis of silica nanoparticles by capillary electrophoresis coupled to an evaporative light scattering detector
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R.C. Rodríguez Martín-Doimeadios, Nuria Rodríguez-Fariñas, Mohammed Zougagh, Ángel Ríos, and Carlos Adelantado
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Aqueous solution ,Chromatography ,010401 analytical chemistry ,Analytical chemistry ,Nanoparticle ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Mass spectrometry ,01 natural sciences ,Biochemistry ,Buffer (optical fiber) ,0104 chemical sciences ,Analytical Chemistry ,chemistry.chemical_compound ,Capillary electrophoresis ,chemistry ,Chromatography detector ,Environmental Chemistry ,Methanol ,0210 nano-technology ,Ammonium acetate ,Spectroscopy - Abstract
A simple and rapid methodology has been developed to identify and separate silica nanoparticles (SiO2NPs) of different sizes in aqueous solution by capillary zone electrophoresis coupled to an evaporative light scattering detector (CE-ELSD). SiO2NPs were separated using 3 mM ammonium acetate buffer, containing 1% methanol at pH 6.9. SiO2NPs of 20, 50 and 100 nm were successfully separated under the optimum experimental conditions. CE coupled to ELSD has been proven to be an effective separation technique to determine particles with such small sizes, although the peaks are very close to each other, and it is a promising technique that may allow the separation of other types of nanoparticles. Confirmation by TEM and quantification of the SiO2 content was also carried out by inductively coupled plasma-mass spectrometry (ICP-MS). The new method was applied to the analysis of real samples, in order to assess its ability to avoid matrix effects in the determination of SiO2NPs in these kinds of samples.
- Published
- 2015
18. The Role of Earthworms in Mercury Pollution Soil Assessment
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R.C. Rodríguez Martín-Doimeadios, Nuria Rodríguez Fariñas, Francisco Javier Guzmán Bernardo, and María Jiménez Moreno
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Pollution ,Pollutant ,media_common.quotation_subject ,Aquatic ecosystem ,chemistry.chemical_element ,Soil contamination ,Mercury (element) ,Food chain ,chemistry ,Environmental chemistry ,Environmental science ,Terrestrial ecosystem ,Bioindicator ,media_common - Abstract
Mercury (Hg) is a global pollutant with different highly toxic chemical forms that can be bioaccumulated and biomagnified. Up to now most studies on Hg pollution have focused on aquatic ecosystems, and this is why little information about Hg in terrestrial ecosystems is currently available. However, the impact of Hg pollution on the terrestrial environment and food chain is of great interest for its human health implications. In this context, earthworms, which constitute a major component in soil ecosystems and act as a food source for a wide variety of organisms, are an excellent option to study Hg biochemistry in terrestrial ecosystems. The use of earthworms as bioindicators of Hg soil pollution involves a wide number of variables to be considered since the metal–biota interaction is very complicated in this case. Therefore, the aim of this chapter is to review the role of earthworms as bioindicators of Hg pollution in soils.
- Published
- 2014
19. Micellar electrokinetic capillary chromatography for the determination of Viagra and its metabolite (UK-103,320) in human serum
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Nuria Rodríguez Fariñas, Juan José Berzas Nevado, Juana Rodríguez Flores, Gregorio Castañeda Peñalvo, Dirección General de Enseñanza Superior e Investigación Científica (España), and Ministerio de Educación y Ciencia (España)
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Male ,Phosphodiesterase Inhibitors ,Metabolite ,Clinical Biochemistry ,Pyrimidinones ,Electrolyte ,Biochemistry ,Piperazines ,Sildenafil Citrate ,Micellar electrokinetic chromatography ,Analytical Chemistry ,chemistry.chemical_compound ,Humans ,Sulfones ,Sodium dodecyl sulfate ,Micelles ,Detection limit ,Chromatography ,Chemistry ,Elution ,Osmolar Concentration ,Temperature ,Electrophoresis, Capillary ,Sodium Dodecyl Sulfate ,Serum samples ,Purines ,Methanol - Abstract
Micellar electrokinetic capillary chromatography (MEKC) was investigated for the determination of Viagra (sildenafil citrate, SC) and its metabolite (UK-103,320) in human serum in a concentration range of clinical interest. For MEKC, human serum samples spiked with SC and UK were obtained directly after elution with methanol from a tC18 cartridge. The extract was evaporated and regenerated in a solution 1 mM of phosphate buffer (pH 12.3) which contained a methanol percentage of 20% that was analyzed using phosphate buffer (pH 12.3, 10 mM) containing 30 mM sodium dodecyl sulfate (SDS) as separation electrolyte and a fused-silica capillary. This method gave satisfactory interday precision with respect to migration times relative standard deviation (RSD, We are indebted to the DGES of the Ministerio de Educación y Ciencia of Spain for financial support (Project PB-97-0431).
- Published
- 2001
20. Mercury exposure and mechanism of response in large game using the Almadén mercury mining area (Spain) as a case study
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Rafael Mateo, Juan José Berzas Nevado, Jaime Rodríguez-Estival, Nuria Rodríguez Fariñas, R.C. Rodríguez Martín-Doimeadios, María J. Patiño Ropero, and Junta de Comunidades de Castilla-La Mancha
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Sus scrofa ,chemistry.chemical_element ,Biology ,Wild boar ,Biochemistry ,Mining ,Selenium ,Animal science ,Molar ratio ,biology.animal ,Animals ,Tissue Distribution ,General Environmental Science ,urogenital system ,Ecology ,Oxidative stress biomarkers ,Deer ,Environmental Exposure ,Mercury ,MERCURY EXPOSURE ,Antioxidant vitamins ,Mercury (element) ,chemistry ,Spain ,Total hg ,Cervus elaphus ,Environmental Pollutants ,Red deer - Abstract
Mercury (Hg) accumulation, transfer, defense mechanism and adverse effects were studied in red deer (Cervus elaphus) and wild boar (Sus scrofa) from the Almadén mining district (Spain), the largest (285,000. t of Hg) and the oldest (more than 2000 years) Hg mine/refining operation site in the world. Red deer (n=168) and wild boar (n=58) liver, kidney, bones (metacarpus), testis and muscle were analyzed for total Hg and selenium (Se) within a range of distances to the Almadén mining district. The highest Hg concentrations were found in kidney (0.092 and 0.103 οg/g d.w. for red deer and wild boar, respectively) followed by the levels in liver (0.013 and 0.023 οg/g d.w. for red deer and wild boar, respectively). A significant correlation (r=-0.609, p=0.007) was found between Hg concentrations and distance to the Almadén Hg mining district. However, both red deer and wild boar closest to the mining area still showed mercury concentrations well below the concentration associated with clinical signs of Hg poisoning. Highest Se concentrations were found in kidney (2.60 and 6.08 οg/g in red deer and wild boar, respectively) and testis (2.20 οg/g in red deer). For selenium, differences between red deer and wild boar were statistically significant (p0.001 for red deer and r=0.567, p=0.005 for wild boar). Liver GSSG concentrations were negatively correlated to total mercury and Hg:Se molar ratio in male deer, which could indicate a hormetic response to Hg exposure. Moreover, a positive association was found between the antioxidant element Se and antioxidant vitamins in red deer tissues., M.J. Patiño Ropero and J. Rodríguez-Estival acknowledge the Junta de Comunidades de Castilla-La Mancha for their Ph.D. fellowships.
- Published
- 2011
21. Biospeciation of tungsten in the serum of diabetic and healthy rats treated with the antidiabetic agent sodium tungstate
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Nuria Rodríguez-Fariñas, M. Milagros Gómez-Gómez, Joan J. Guinovart, Jorge Domínguez, Carmen Camara-Rica, and Benito Cañas-Montalvo
- Subjects
Protein Denaturation ,Size-exclusion chromatography ,Administration, Oral ,Ultrafiltration ,Tungsten ,Analytical Chemistry ,Gel permeation chromatography ,chemistry.chemical_compound ,Tungstate ,Protein purification ,Diabetes Mellitus ,Animals ,Hypoglycemic Agents ,Sodium tungstate ,Rats, Wistar ,Serum Albumin ,Chromatography ,Protein Stability ,Albumin ,Química analítica ,Tungsten Compounds ,Glutathione ,Rats ,Matrix-assisted laser desorption/ionization ,chemistry ,Health ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Urea ,Chromatography, Gel ,Female - Abstract
It is known that oral administration of sodium tungstate preserves the pancreatic beta cell function in diabetic rats. Healthy and streptozotocin-induced diabetic rats were treated with sodium tungstate for one, three or six weeks, after which the species of W in serum, were analysed. An increase in serum W with treatment time was observed. After six weeks, the serum W concentration in diabetic rats (70 mg L(-1)) was about 4.6 times higher than in healthy specimens. This different behaviour was also observed for Cu accumulation, while the Zn pattern follows the contrary. The patterns observed in the retention of Cu and Zn may be attributable to a normalization of glycaemia. The speciation analysis of W was performed using 2D separations, including an immunoaffinity packing and a SEC (Size Exclusion Chromatography) column coupled to an ICP-MS (Inductively Coupled Plasma Mass Spectrometry) for elemental detection. Ultrafiltration data together with SEC-ICP-MS results proved that around 80% of serum W was bound to proteins, the diabetic rats registering a higher W content than their healthy counterparts. Most of the protein-bound W was due to a complex with albumin. An unknown protein with a molecular weight higher than 100 kDa was also found to bind a small amount of W (about 2%). MALDI-TOF (Matrix-Assisted Laser Desorption Ionization Time-of-Flight) analysis of the desalted and concentrated chromatographic fractions confirmed albumin as the main protein bound to tungstate in rat serum, while no binding to transferrin (Tf) was detected. The interaction between glutathione and W was also evaluated using standard solutions; however, the formation of complexes was not observed. The stability of the complexes between W and proteins when subjected to more stringent procedures, like those used in proteomic methodologies (denaturing with urea or SDS, boiling, sonication, acid media, reduction with β-mercaptoethanol (BME) or DTT (dithiotreitol) and alkylation with iodoacetamide (IAA), was also evaluated. Our results indicate that the stability of the complexes between W and proteins is not too high enough to remain unaltered during protein separation by SDS-PAGE in denaturing and reducing conditions. However, the procedures for in-solution tryptic digestion and for ESI-MS analysis in MeOH/H(2)O/with 0.1% formic acid could be used for protein identification without large loss of binding between W and proteins.
- Published
- 2011
22. Study of tungstate–protein interaction in human serum by LC–ICP-MS and MALDI-TOF
- Author
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M. Milagros Gómez-Gómez, Nuria Rodríguez-Fariñas, and Carmen Camara-Rica
- Subjects
HEPES ,Serum ,Chromatography ,Size-exclusion chromatography ,Blood Proteins ,Química analítica ,Tungsten Compounds ,Mass spectrometry ,Biochemistry ,Mass Spectrometry ,Analytical Chemistry ,Gel permeation chromatography ,chemistry.chemical_compound ,Matrix-assisted laser desorption/ionization ,Kinetics ,chemistry ,Tungstate ,Humans ,Sodium tungstate ,Inductively coupled plasma mass spectrometry ,Chromatography, Liquid ,Protein Binding - Abstract
Oral administration of sodium tungstate is an effective treatment for type 1 and 2 diabetes in animal models; it does not incur significant side effects, and it may constitute an alternative to insulin. However, the mechanism by which tungstate exerts its observed metabolic effects in vivo is still not completely understood. In this work, serum-containing proteins which bind tungstate have been characterized. Size exclusion chromatography (SEC) coupled to inductively coupled plasma mass spectrometry (ICP-MS) with a Phenomenex Bio-Sep-S 2000 column and 20 mM HEPES and 150 mM NaCl at pH 7.4 as the mobile phase was chosen as the most appropriate methodology to screen for tungsten-protein complexes. When human serum was incubated with tungstate, three analytical peaks were observed, one related to tungstate-albumin binding, one to free tungstate, and one to an unknown protein binding (MW higher than 300 kDa). Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometric analysis of the tungsten-containing fractions collected from SEC-ICP-MS chromatograms, after desalting and preconcentration processes, confirmed the association of tungstate with albumin and the other unknown protein. [figure: see text]
- Published
- 2008
23. Mercury speciation in whole blood by gas chromatography coupled to ICP-MS with a fast microwave-assisted sample preparation procedure.
- Author
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Jairo L. Rodrigues, Carolina Rodríguez Alvarez, Nuria Rodríguez Fariñas, Juan J. Berzas Nevado, Fernando Barbosa Jr, and Rosa C. Rodríguez Martín-Doimeadios
- Subjects
CHEMICAL speciation ,MERCURY ,GAS chromatography ,BLOOD testing ,INDUCTIVELY coupled plasma mass spectrometry ,MICROWAVES ,METHYLMERCURY - Abstract
A simple and fast method is described for simultaneous determination of methylmercury (MeHg), ethylmercury (Et-Hg) and inorganic mercury (Ino-Hg) in blood samples by using capillary gas chromatography-inductively coupled plasma mass spectrometry (GC-ICP-MS) after derivatization and alkaline digestion. Closed-vessel microwave assisted digestion conditions with tetramethylammonium hydroxide (TMAH) have been optimized. Derivatization by using ethylation and propylation procedures have also been evaluated and compared. The absolute detection limits (using a 1 μL injection) obtained by GC-ICP-MS with ethylation were 40 fg for MeHg and Ino-Hg, respectively, and with propylation were 50, 20 and 50 fg for MeHg, Et-Hg and Ino-Hg, respectively. Method accuracy is traceable to Standard Reference Material (SRM) 966 Toxic Metals in Bovine Blood from the National Institute of Standards and Technology (NIST). Additional validation is provided based on the comparison of results obtained for mercury speciation in blood samples with the proposed procedure and with a previously reported LC-ICP-MS method. With the new proposed procedure no tedious clean-up steps are required and a considerable improvement of the time of analysis was achieved compared to other methods using GC separation. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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