Pilar Bermejo-Barrera

Pilar Bermejo-Barrera
University of Santiago de Compostela | USC · Department of Analytical Chemistry, Nutrition and Bromatology

About

362
Publications
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7,220
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Additional affiliations
January 1990 - December 2016
University of Santiago de Compostela
Position
  • Head of the research group of Trace Elements, Spectroscopy and Speciation

Publications

Publications (362)
Article
Intensive production of nanomaterials, especially metallic nanoparticles (MNPs), and their release into the environment pose several risks for humans and ecosystem health. Consequently, high-efficiency analytical methodologies are required for control and characterization of these emerging pollutants. Single-particle inductively coupled plasma – ma...
Article
Seaweed can bioaccumulate nanomaterials that would be transferred to the trophic chain. This work describes the optimization of a method for the separation of silver nanoparticles (AgNPs) from seaweed using an ultrasound-assisted enzymatic hydrolysis method and ulterior determination by single particle inductively coupled plasma mass spectrometry (...
Article
The use of zinc oxide (ZnONPs) and titanium dioxide nanoparticles (TiO2NPs) in cosmetic formulations to obtain protection against the sun's UV radiation has become a common practice owing to their high photo-stability and the absence of allergic reactions of these nanomaterials. The manufacturing of cosmetics modified with nanoparticles has been re...
Article
In recent decades, the remarkable thermal, electronic, optical and mechanical properties of smart materials have attracted the attention of analytical chemists intending to address problems found in metal determination in food (use of time-consuming procedures and expensive techniques to reach the low limits of detection required for quality contro...
Article
Full-text available
Metals, metallic compounds, and, recently, metallic nanoparticles appear in textiles due to impurities from raw materials, contamination during the manufacturing process, and/or their deliberate addition. However, the presence of lead, cadmium, chromium (VI), arsenic, mercury, and dioctyltin in textile products is regulated in Europe (Regulation 19...
Article
Analytical methods based on dynamic-reaction cell (DRC) technology using ammonia as a reaction gas have been developed for the determination of ultra-trace Ti, Zn, Cu and Ag by inductively coupled plasma mass spectrometry (ICP-MS). Challenging spectral interferences from complex matrices were demonstrated to be overcome by DRC, and several DRC appr...
Article
Full-text available
Fruit juices were analysed for their contents in a series of essential and toxic elements (Al, As, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Na, Ni, Pb, V, Sb, Mo and Zn). Samples were subjected to microwave-assisted acid digestion (HNO3/H2O2), and analytes were determined by inductively coupled plasma optical emission spectrometry (ICP-OES), in axial mode,...
Article
The European Food Safety Authority has published a guidance regarding risk assessment of nanomaterials in food and feed. Following these recommendations, an in vitro gastrointestinal digestion has been applied to study the biopersistence of TiO2 and Ag NPs in standards, molluscs and surimi. TiO2 NPs standards and TiO2 NPs/ TiO2 microparticles from...
Article
In this study, a first attempt for isolating and determining (characterising) background levels of titanium dioxide nanoparticles (TiO2 NPs) in seaweed has been developed by using single particle inductively coupled plasma – mass spectrometry (SP-ICP-MS). Seaweeds were processed using an optimised ultrasound assisted extraction (UAE) procedure base...
Article
A selective molecularly imprinted polymer (MIP) adsorbent was synthesised and used in a batch micro-solid phase extraction format for isolating aflatoxins (AFB1, and AFB2) from non-dairy beverages before liquid chromatography-tandem mass spectrometry determination. MIP synthesis (precipitation polymerization in 3 : 1 acetonitrile/toluene as a porog...
Article
A method based on asymmetric flow field-flow fractionation (AF4) coupled to ultraviolet-visible (UV-vis) spectroscopy and inductively coupled plasma mass spectrometry (ICP-MS) has been developed for silver nanoparticles (Ag NPs) detection and quantification in bivalve molluscs. Samples were pre-treated using a conventional enzymatic (pancreatin and...
Article
Titanium dioxide nanoparticles (TiO2 NPs) are widely used in industry as a white pigment (paints, paper industry and toothpastes), photocatalysts (environmental decontamination and photovoltaic cells), inorganic UV filter (sunscreens and personal care products) and as a food additive (E171) and antimicrobial food packaging material. Silver nanopart...
Article
The use of magnetic nanoparticles (MNPs) as adsorbent/separation agents for the removal of heavy metal-based compounds from aqueous environments has received much attention in the last few years. However, in most cases, the designed particles present large dimensions (at least several tens of nm) in order to provide them with high magnetic energy a...
Article
Trace elements in dried blood spots (DBS) from new-born were determined by laser ablation (LA) coupled with inductively coupled mass spectrometry (ICP-MS), and data was subjected to chemometric evaluation in an attempt to classify healthy new-born and new-born suffering metabolic disorders. Unsupervised [principal component analysis (PCA), and clus...
Article
Bioaccessibility of trace elements (Li, Be, Ti, Ga, Cu, Ag, Hg, Cd, Cs, Pt, Tl, Pb, As, Cr, Co, Ni, V, Se, Sn and Sb) and major elements (Rb, Ba, Al, Fe, Zn, Si, Ca, Mg, Mn, Mo, Sr, P and K) in tea infusions has been assessed using an in vitro dialyzability protocol. Gastric simulation (using pepsin solution) and intestinal simulation (using pancre...
Article
In contrast to most of essential and heavy metals, mercury levels in seaweed are very low, and pre-concentration methods are required for an adequate total mercury determination and mercury speciation in this foodstuff. An ionic imprinted polymer-based solid phase extraction (on column) pre-concentration procedure has been optimized for mercury spe...
Article
A dispersive micro solid phase extraction approach using a molecularly imprinted polymer as an adsorbent has been developed for pre-concentrating aflatoxins from cultured fish. Aflatoxins were first isolated from fish muscle and liver by an ultrasound assisted extraction procedure using a 60:40 acetonitrile/0.1M KH2PO4 aqueous buffer (pH 6.0) mixtu...
Article
A sensitive, precise and selective method for the analysis of butyl benzyl phthalate (BBP), diethyl phthalate (DEP), dibutyl phthalate (DBP), and dimethyl phthalate (DMP) in tea samples has been applied. Molecularly Imprinted Polymer-Solid Phase Extraction (MIP-SPE) has been used for the separation and preconcentration of these compounds. Phthalate...
Article
This study combines ultrasound-assisted extraction and vortex-assisted dispersive micro-solid phase extraction using an ionic imprinted polymer as a selective sorbent for rapid isolation and pre-concentration of inorganic arsenic species (As(III) and As(V)) in extracts from rice samples prior to their determination by high performance liquid chroma...
Article
A procedure for the size characterization and quantification of titanium dioxide (TiO2) nano- and microparticles by Asymmetric Flow Field-Flow Fractionation (AF4) coupled to Dynamic Light Scattering (DLS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is described. Different strategies for size characterization with size standards and th...
Article
Rice is the principal food in many countries for billions of people and one of the most consumed cereals in the world. The rice plant has the ability to bioaccumulate essential and toxic trace elements such as arsenic. The toxicity of the elements depends not only on their concentration but also on their chemical form and their bioavailability. The...
Article
Objective The objectives of the study were to determine whether low plasma selenium levels (<63 μg/L according to population-based reference interval) were associated with poorer survival among adult patients with end-stage renal disease (ESRD) on dialysis treatment and to study whether plasma selenium behaved as a biomarker of mortality risk indep...
Article
Non-essential trace elements, especially mercury (Hg) and arsenic (As), and their speciation analysis in fish and fishery products have gained increasing attention regarding human exposure, risk assessment and toxicological endpoints. Reliable, robust and sophisticated hyphenated laboratory instrumentation is available today, providing very low qua...
Article
Full-text available
The present study deals with the investigation of Cu2+, Ni2+ and Pd2+ chelating potential of the Schiff base, (E)-N-(2-((2-hydroxybenzylidene)amino)benzyl)-4-methylbenzenesulfonamide (H2SB). Crystal structures of Ni(HSB)2, Pd(HSB)2 and Cu(HSB)2 have been elucidated from single crystal X-ray diffraction data. NMR spectroscopy showed the presence of...
Article
An analytical procedure using low-cost instrumentation (fluorescence/phosphorescence spectrophotometer) has been developed to assess total mercury in fishery products. Determinations were based on the room temperature phosphorescence (RTP) quenching of a composite Ph-QDs consisting of phenobarbital-containing polymer/silica coated Mn-doped ZnS quan...
Article
Low levels of inorganic arsenic [As(III) and As(V)] in fishery products have been selectively isolated from fish extracts (1.0 g of wet fish samples pre-treated with 10 mL of 1:1 methanol/water under sonication at 25 °C for 30 min) by ionic imprinted polymer (IIPs) based solid phase extraction procedure (on-column mode). The selective adsorbent was...
Article
A novel room temperature phosphorescence chemosensor probe has been successfully developed and applied to the selective detection and quantification of inorganic arsenic (As(III) plus As(V)) in fish samples. The prepared material (IIP@ZnS:Mn QDs) was based on Mn-doped ZnS quantum dots coated with (3-aminopropyl) triethoxysilane and an As(III) ionic...
Article
Despite aflatoxins contamination in feedstuff is a well‐known problem, and hence these residues are controlled in poultry products, there are scarce information regarding the presence of these toxic substances in aquaculture fish, facilities which use several feedstuff for fish breeding. A simple, rapid, and sensitive method has been therefore deve...
Article
Possibilities of room temperature spectrometry based on Mn-doped ZnS quantum dots coated with a molecularly imprinted polymer based nanosensor have been explored for the sensitive and selective determination of aflatoxins. Synthesized polymeric nanoparticles exhibit intense room temperature phosphorescence (total decay time of 0.004 s) and aflatoxi...
Article
An analytical method for the separation and determination of titanium dioxide nanoparticles in water samples has been developed. The separation was performed by Cloud Point Extraction (CPE) with Triton X-114. Titanium dioxide nanoparticles and ionic titanium were analysed in the surfactant rich phase and surfactant poor phase respectively, by induc...
Article
A combined procedure based on using ultrasounds for target isolation followed by porous membrane-protected micro solid phase extraction using a molecularly imprinted polymer as an adsorbent has been developed as a highly selective extraction and clean-up procedure for isolating aflatoxins B1, B2, G1, and G2 from fish feed before ultra-high-performa...
Article
Advances on nanometrology require reliable sample pre-treatment methods for extracting/isolating nanomaterials from complex samples. The current development deals with a discontinuous ultrasonication (60% amplitude, 15 cycles of ultrasound treatment for 59 s plus relaxing stage for 59 s, 20 mL of methanol) method for a fast and quantitative extract...
Article
A method based on single-particle inductively coupled plasma mass spectrometry (sp-ICPMS)using a dwell time 50 μs for acquisition has been developed for silver nanoparticles (Ag NPs)determination and characterization in bivalve molluscs. Ultrasound assisted enzymatic hydrolysis has been proposed for a fast isolation of Ag NPs from seafood using pan...
Article
Full-text available
Redox properties enable copper to perform its essential role in many biological processes, but they can also convert it into a potentially hazardous element. Its dyshomeostasis may have serious neurological consequences, and its possible involvement in Parkinson’s disease and other neurodegenerative disorders has been suggested. The in vitro and ex...
Article
Synthesis of molecularly imprinted polymers (MIPs) implies a previous pre-polymerization stage in which the template (the molecule for which the MIP offers the specific recognition cavities) interacts with the adequate functional monomer, just before the addition of the cross-linker and the initiator for performing the polymerization synthesis. The...
Article
Discrete sampling based on the flow injection options offered by advanced autosamplers has been tested and applied for the direct analysis of low volume samples (human serum) for multi-elemental purposes (simultaneous Al, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Ni, Pb, Rb, Se, V, and Zn assessment). Serum samples (200 µL aliquots) were direc...
Article
Synthesized molecularly imprinted polymer (MIP) materials have been anchored on the surface of PEG-Mn-doped ZnS quantum dots (QDs) to develop a fluorescence probe for aflatoxins (AFs) recognition/determination in non-dairy beverages. MIP synthesis used 5,7-dimethoxycoumarin (DMC) as a dummy template molecule, and methacrylic acid (MAA) as a functio...
Article
A simple and reliable analytical method using instrumentation available in most of the laboratories has been developed for the separation and determination of silver nanoparticles in water samples. Cloud point extraction (CPE) was used for the separation of silver nanoparticles (AgNPs) from the sample and these nanoparticles were then determined by...
Article
Full-text available
A reliable method based on high-performance liquid chromatography-tandem mass spectrometry has been developed for the assessment of coca alkaloids/metabolites [cocaine (COC), benzoylecgonine (BE), cocaethylene (CE), ecgonine methyl ester (EME), anhydroecgonine methyl ester (AEME), tropococaine (TRO), transcinnamoylcocaine (trCIN), cuscohygrine (CUS...
Article
A reliable sample pre-treatment based on enzymatic hydrolysis has been fully optimized and validated for TiO2 NPs isolation and determination/characterization in surimi (crab sticks). Efficient extractions have been found when using a pancreatin/lipase mixture at pH 7.4 and 37 °C for 12 h under continuous stirring. The proposed sample pre-treatment...
Article
Size exclusion chromatography (SEC) hyphenated to inductively coupled plasma – mass spectrometry (ICP-MS), as a specific detector for metals, has been used for monitoring and determining metal-low molecular weight organic compound (LMWC) complexes in natural wines. SEC with UV detection (wavelength of 205 nm) was used for monitoring organic compoun...
Article
Bioavailability of elements in ‘natural’ wines from Chile’s Itata Valley has been assessed using an in vitro dialyzability approach. The red wines (fifteen samples) were of the Cinsault, Cabernet Sauvignon, Carmènére, Malbe, and Pinot noir varieties. All white wines (three samples) were of the Muscat of Alexandria variety. Inductively coupled plasm...
Article
Synthetic cathinones are a type of drugs belonging to group of "new psychoactive substances" (NPSs). The illicit market of these substances is characterized by the continuous introduction in the market of new analogs to evade legislation and to avoid be detected. New screening and confirmation assays are therefore needed, mainly in forensic/clinica...
Article
ISO/IDF procedures were adjusted to extract the fat from milk samples and derivatise it into fatty acid methyl esters for their analysis by two gas chromatography methods: one for the determination of cis‐9,trans‐11‐octadecadienoic acid; another, to study the fatty acid (FA) profile of samples. Both methods exhibited good precision, produced reliab...
Article
A novel approach for serum analysis by dried matrix spot (DMS) technique is proposed. The methodology consists of sampling filter paper discs (2.7 mm in diameter) containing the large amount of serum retained after a single spotting. Several oxidizers (sodium chlorate, sodium azide, acetic acid, formic acid, 1-butyl-3-methylimidazoliumm chloride/br...
Article
Applicability of single-particle inductively coupled plasma mass spectrometry (sp-ICP-MS) using dwell times equal to or shorter than 100 μs has been tested for assessing titanium dioxide nanoparticles (TiO2 NPs) in bivalve mollusks. TiO2 NPs isolation from fresh mollusk tissues was achieved by ultrasound assisted enzymatic hydrolysis procedure usin...
Article
Several molecularly imprinted polymers (MIPs) have been synthesized for the first time using various synthetic cannabinoids (JWH007, JWH015 and JWH098) as template molecules. Ethylene dimethacrylate (EDMA) was used as a functional monomer for all cases. Similarly, divinylbenzene (DVB) and 2,2'-azobisisobutyronitrile (AIBN) were used as cross-linker...
Article
An in vitro dialyzability approach has been undertaken to elucidate the bioavailable fraction of the total polyphenols (TPs) of edible nuts and seeds. The TP contents in samples and in dialyzates were assessed by the Folin-Ciocalteu spectrophotometric method. Antioxidant activity was determined in selected samples, using a modified method against T...
Article
A molecularly imprinted polymer – Mn-doped ZnS quantum dot-based fluorescence probe for cocaine abuse screening has been prepared and applied to complex samples such as serum and oral fluid. The fluorescent sensing material was prepared by anchoring a selective MIP for COC on the surface of polyethylene glycol (PEG) modified Mn-doped ZnS quantum do...
Article
An easily synthesized fluorescent probe for copper in aqueous samples, with short response time and at neutral pH, has been investigated. Through the chelation of Cu2+ ions or by binding to CuO nanoparticles the fluorescence emission of the 2 (aminomethyl)aniline derivative H2L is quenched by over 50%. Spectroscopic determination of association con...
Article
Background: This review describes the use of molecularly imprinted polymers (MIPs) as tailor-made adsorbents for developing micro-solid phase extraction (µ-SPE) procedures when isolat-ing/assessing organic pollutants, drugs, and bioactive compounds from environmental, food, and clini-cal/forensic samples. Objective: Developments in MIP-µ-SPE are fo...
Article
Due to the high levels of iodine presents in seaweed the ingestion of large amount of this type of food can produce excessive intake of iodine. However, the food after ingestion suffers different chemistry and physical processes that can modify the amount of iodine that reaches the systemic circulation (bioavailability). Studies on the bioavailabil...
Article
An approach by laser ablation (LA) coupled with inductively coupled mass spectrometry (ICP-MS) for multi-element determination in whole blood is described. The method allows quantitative determination of several major (K, Na and S), minor (Ca, Cu, Fe, Mg, P, Rb and Zn), and trace elements (Al, As, Ba, I, Li, Pb, Sb, V and Tl) in dried blood spot (D...
Article
This work proposes the use of high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC-ICP-MS) for simultaneous speciation of arsenic and chromium in iron supplements used for the treatment of anemia. The sample preparation procedure recommended for the total determination of arsenic and chromium was esta...
Article
A method for the determination of four phthalates in water and wine samples by liquid chromatography-mass spectrometry has been developed. The four phthalates studied were dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), diethyl phthalate (DEP) and dimethyl phthalate (DMP). A preconcentration step was necessary due to the low levels of these...
Article
Full-text available
In this study, a molecularly imprinted polymer based on the formation of the phenobarbital- methylmercury complex was used as a solid phase extraction sorbent for the preconcentration of mercury in waters and subse- quent analysis by CV-ICP-OES. A number of important operating parameters were optimized: pH of the sample (pH = 8), sample flow rate,...
Article
Full-text available
Aqueous soluble arsenic species in Atlantic edible sea- weeds have been quantified by high performance liquid chro- matography–inductively coupled plasma mass spectrometry (HPLC–ICP-MS). A pressurized high-temperature water extrac- tion (PHWE) method has been developed for arsenic species. The significance of several para- meters involved in the ar...
Article
Full-text available
A molecularly imprinted polymer (MIP) selective for cannabinoids [Δ(9)-tetrahydrocannabinol (Δ9-THC), 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol (Δ9-THC-COOH), and 11-hydroxy-Δ(9)-tetrahydrocannabinol (Δ9-THC-OH)] has been synthesized, fully characterized, and applied to the assessment of plasma and urine analysis of marijuana abuse by high perform...
Article
Full-text available
In this study, a molecularly imprinted polymer based on the formation of the phenobarbitalmethylmercury complex was used as a solid phase extraction sorbent for the preconcentration of mercury in waters and subsequent analysis by CV-ICP-OES. A number of important operating parameters were optimized: pH of the sample (pH = 8), sample flow rate, elut...
Chapter
This chapter reviews the analytical methodology that used for arsenic speciation in marine food as well as bioavailability studies performed for arsenic species in this type of samples. During the first step of sample preparation, the byssus, shell, or both are removed from mollusk samples, while bone and entrails are removed from fish samples. The...
Article
Metalloproteins and metal–protein complexes play key roles in all organisms. For example, certain metalloproteins are involved in metal homeostasis and detoxification, or oxidative stress protection; whereas, metals serve as essential cofactors in a large number of metal–protein complexes. Advances in analytical instrumentation as well as informati...
Article
A simple sample pre-treatment method based on solid phase microextraction (SPME) and gas chromatography–mass spectrometry (GC-MS) has been optimized and validated for the assessment of 15 residual solvents (2-propanol, 2-methylpentane, 3-methylpentane, acetone, ethyl acetate, benzene, hexane, methylcyclohexane, methylcyclopentane, m-xylene, propyl...
Article
In this study, the content of sulfur in bovine serum albumin and L-cysteine was determined using high-resolution continuum source molecular absorption spectrometry of the CS molecule, generated in a reducing air-acetylene flame. Flame conditions (height above the burner, measurement time) were optimized using a 3.0% (v/v) sulfuric acid solution. A...
Article
Full-text available
A method for total As and Cr determination in seawater sam- ples has been developed. As and Cr were measured using the seaFAST2 automated sample introduction system coupled to an ICP-MS. The sampling system allows on-line sample dilution (10 times) before introduction into the ICP-MS. Calibration was performed using the standard addition method, wo...
Article
A selective molecularly imprinted polymer synthesized for the selective retention of cocaine (COC) and its metabolites [benzoylecgonine (BZE), ecgonine methyl ester (EME), and cocaethylene (CE)] was used as a solid adsorbent for assessing cocaine abuse by plasma analysis. The MIP beads (50 mg) were loaded inside a cone shaped device made of a polyp...
Article
The quality of the quantitative information in single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS) depends directly on the number concentration of the nanoparticles in the sample analyzed, which is proportional to the flux of nanoparticles through the plasma. Particle number concentrations must be selected in accordance with th...