Rosa M Alonso

Universidad del País Vasco / Euskal Herriko Unibertsitatea | UPV/EHU · Analytical Chemistry

From its introduction in Europe, Vespa velutina nigrithorax has become an invasive species, since it is a predator of native fruits and insects, most of the latter being honeybees. Despite the knowledge on the life cycle of this hornet, Asian hornet behaviour is not well understood, since in vivo studies on this species are quite difficult to perfo...

Binary gas mixture of N2 and trans-1,1,1,4,4,4-hexafluorobut-2-ene (HFO4E) is presented as an alternative to SF6 in medium-voltage electrical equipment. Its stability was tested under different conditions. No change was observed in the gas mixture after a permanent AC voltage of 30 kV applied for two years or during the making operations with a sta...

A deep knowledge about the biological development of children is essential for appropriate drug administration and dosage in pediatrics. In this sense, the best approximation to study organ maturation is the analysis of tissue samples, but it requires invasive methods. For this reason, surrogate matrices should be explored. Among them, plasma emerg...

Aspergillus fumigatus onddoak sortutako aspergilosi inbaditzailea mehatxua da immunoeskasia duten gaixoentzat. Azkeneko ikerketa batzuen arabera, fumagilinak, onddoak sortutako mikotoxinak, gaixotasunaren hedapenarekin zerikusia duela ikusi da. Hori dela eta, konposatu honen determinazioa lagungarria izan daiteke bai gaixotasunaren mekanismoak hobe...

In this work, a low toxicity deep eutectic solvent-based ferrofluid is presented for the first time as magnetic fluid to be used as an efficient solvent in liquid-based microextraction techniques. This ferrofluid is made of a hydrophobic deep eutectic solvent, composed by menthol and thymol in a 1:5 molar ratio as carrier solvent, and oleic acid-co...

Regarding the use of SF6 in medium voltage switchgear (MVS), a review of alternatives was encouraged by the European Parliament in Regulation No 517/2014. This is aimed at a new regulatory change, that is expected soon, which will include its prohibition, similar to what has happened with other fluorinated greenhouse gases in other fields, like ref...

Exercise induces free radicals’ overproduction and therefore, an enhancement of oxidative stress, defined as an imbalance between the production of reactive species and the intrinsic antioxidant defense. Redox activity of reactive species plays an important and a positive role on exercise adaptation, but these species at very high concentrations ha...

The activity of fumagillin, a mycotoxin produced by Aspergillus fumigatus, has not been studied in depth. In this study, we used a commercial fumagillin on cultures of two cell types (A549 pneumocytes and RAW 264.7 macrophages). This toxin joins its target, MetAP2 protein, inside cells and, as a result, significantly reduces the electron chain acti...

In this work, binary and ternary gas mixtures of 1,3,3,3-tetrafluoropropene, HFO-1234ze(E), and perfluoro-(3-methylbutan-2-one), CF3C(O)CF(CF3)2, with CO2 and synthetic air, are presented as alternatives to SF6 in medium-voltage electrical equipment. They were used in four medium-voltage switchgear cubicles replacing SF6 gas, and after a period of...

Fumagillin is a biomolecule produced by Aspergillus fumigatus that is gaining relevance due to its connection with invasive aspergillosis. The determination of this molecule might help to understand the propagation of this disease and study its use as a potential biomarker. In spite of the interest of fumagillin in microbiological research, no quan...

Insect plagues are a problem often hard to solve due to the harmful effects caused by the pesticides used to combat them. Consequently, the pesticide market is increasingly trying to develop new technologies to prevent the unwanted effects that common plague treatments usually bring with them. In this work, four specific bioattractants of Musca dom...

Liver plays an important role in drug metabolism, so studying the grade of maturation of this organ would help to develop more appropriate dosing regimens for paediatric populations. Nevertheless, considering the invasive nature of liver analyses there are obvious ethical boundaries, particularly in babies and children. In this work, we investigate...

Introduction Several software packages containing diverse algorithms are available for processing Liquid Chromatography-Mass Spectrometry (LC–MS) chromatographic data and within these deconvolution packages different parameters settings can lead to different outcomes. XCMS is the most widely used peak picking and deconvolution software for metabolo...

Fumagillin is a mycotoxin produced, above all, by the saprophytic filamentous fungus Aspergillus fumigatus. This mold is an opportunistic pathogen that can cause invasive aspergillosis, a disease that has high mortality rates linked to it. Its ability to adapt to environmental stresses through the production of secondary metabolites, including seve...

Fumagillin is a mycotoxin produced, above all, by the saprophytic filamentous fungus Aspergillus fumigatus. This mold is an opportunistic pathogen that can cause invasive aspergillosis, a disease that has high mortality rates linked to it. Its ability to adapt to environmental stresses through the production of secondary metabolites, including seve...

Dried blood spot (DBS) has lately experienced an increase in its use in bioanalysis due to its several advantages compared with traditional blood sampling methods. Nevertheless, the use of DBS with quantitative purposes is hindered by the heterogeneous distribution of some compounds in the supporting matrix and the dependence of the response on dif...

The increase of fungal resistance to drugs, such as azole family, gave rise to the development of new antifungals. In this context, echinocandins emerged as a promising alternative for antifungal therapies. Following the commercialization of caspofungin in 2001, echinocandins became the first-line therapy for invasive candidiasis in different patie...

Poly(2-ethyl-2-oxazoline) has become an excellent alternative to the use of poly(ethylene glycol) in pharmaceutical formulations due to its valuable physicochemical and biological properties. This work presents a formulation of poorly-water soluble drug, hydrocortisone, using interpolymer complexes and physical blends of poly(2-ethyl-2-oxazoline)s...

A novel gradient reverse phase high performance liquid chromatography tandem mass spectrometry (HPLC/MS-MS) was performed as a method for the determination of dobutamine hydrochloride (DOB) in newborn pig plasma samples. It was developed and validated after optimization of sample treatment and various chromatographic and mass spectrometric conditio...

A pilot study for the investigation of the maturation grade of children has been carried out using plasma samples already analyzed in a previous pharmacokinetic study. By using a meticulous data treatment, possible confounding factors that may hinder the obtained results were identified. By doing so, it was possible to obtain enough evidence to sup...

This work reports the development and validation of an ultra-high-performance liquid chromatography method to separate 11 different cardiovascular drugs: acenocoumarol, amiloride, bisoprolol, fluvastatin, furosemide, glibenclamide, hydrochlorothiazide, rosiglitazone (internal standard), valsartan, verapamil and warfarin. Detection of the analytes w...

XXI. mendeko erronken artean ingurumen-osasunean kalte egin dezaketen arazoei aurre egiteko metodo alternatiboen bilaketa aurkitzen da. Arlo honetan mikrokapsulazioaren abantaila anitzek arazo hauei aurre egiteko baliozko aukera bat erakusten dute. Abantaila garrantzitsuen artean ingurumenean eta ugaztunetan toxikotasunaren murrizketa, langileen ze...

The molecular microencapsulation process, through the formation of the inclusion complex with β-cyclodextrin (β-CD), shows numerous environmental and industrial cost advantages, such as, stability improvement of the active substance, synthesis of water-based products, option of commercializing the final product either in solid state or in solution...

Commercial stabilized slurry of zero-valent iron nanoparticles (nZVI) as well as laboratory-synthesized polymer–stabilized NZVI nanoparticles were used for lindane (γ-hexachlorocyclohexane) degradation studies in aqueous solution. In the present study, polymer-stabilized iron nanoparticles were stabilized using polyethylene glycol (PEG, Mn ~ 400 an...

Lan honetan Odol Tanta Lehorraren (OTLa) laginketa-teknikaren fidagarritasuna ikertu da farmakoen analisirako fotodiodo- eta fluoreszentzia-detektagailuei akoplatutako bereizmen oso altuko likido-kromatografiaren (UHPLC-PDA-FLD) bidez. OTLak, odol-tanta bat kotoi-paperezko euskarri batean jartzean eta lehortzen uztean datzan teknikak, azken urteota...

In this work, the reliability of Dried Blood Spot (DBS) as a sampling technique for drug analysis was studied by Ultra High Performance Liquid Chromatography coupled to Photodiode-Array and Fluorescence Detection (UHPLC-PDA-FLUO). DBS microsampling, a technique based on placing a drop of blood in a cotton support that is allowed to air dry, has lat...

A unique ion chromatographic method using gradient elution is reported to determine chloride, bromide, nitrate, and sulfate in hexafluorosilícic, tetrafluoroboric, hexafluorotitanic, and thexafluorozirconic acids. Industrial samples of the fluorinated acids may contain high levels of fluorinated species at pH values lower than 1.0, which represents...

The great impact of cardiovascular diseases in human health has led to the development of a huge number of drugs and therapies to improve the treatment of these diseases. Cardiovascular drug analysis in biological fluids constitutes an important challenge for analytical scientists. There is a clear need for reliable methods to carry out both qualit...

The codling moth (Cydia pomonella) and navel orangeworm (Amyelois transitella) are insect pests that inflict serious economic damage to California walnuts. Feeding by these larvae causes physical damage to the nut and can lead to contamination by aflatoxigenic fungi. Over the years volatile natural products have played a critical role in efforts to...

In this study, a selective and sensitive high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method requiring low sample volume (≤100 μL) was developed and validated for the quantitative determination of the opioid drug fentanyl in plasma and cerebrospinal fluid (CSF). A protein precipitation extraction with acetonitrile wa...

Eight human plasma preparation protocols were evaluated for their suitability for metabolomic studies by ultra-high-performance liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry: organic solvent protein precipitation (PPT) with either methanol or acetonitrile in 2:1 and 3:1 (v/v) ratios with plasma; solid-p...

The proposed methodology was applied to 114 donors aged 0–90 years old from various geographical areas of the Biscay province (northern Spain) which were characterized by differing environmental conditions and dietary habits. 22 trace elements (Al, As, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, Sb, Se, Sr, Ti, V and Zn) were determined...

Analytical chemistry offers useful tools to solve problems in industrial laboratories caused by traditional methods of analysis. A simple ion chromatographic method has been developed to determine chloride, bromide, nitrate, and sulfate in hexafluorosilicic acid and tetrafluoroboric acid. These materials contain high levels of fluorinated species a...

This article reviews the recent and significant advances in headspace gas chromatography (HS-GC). The evolution and potential industrial applications in the last five years (2008 to present) are reviewed and discussed. The topics include a brief overview of the recent advances in HS-GC techniques and theory, followed by examples of new applications...

Iron nanoparticles (FeNPs) have the high reactive capacity to degrade lindane so as to provide a process that will safely destroy lindane mixed with soil, according to a study at the Department of Physical Chemistry and Analytical Chemistry of the University of the Basque Country in collaboration with Tecnalia

Capillary ion electrophoresis (CIE) with indirect ultraviolet (UV) detection was used for separation and quantification of several inorganic anions such as bromide, chloride, sulphate, nitrite, nitrate, fluoride, and phosphate in different natural and wastewater samples. This paper illustrates setting-up and interpreting a validation methodology fo...

A simple, easy-to-use, efficient and environmentally friendly method has been developed for the simultaneous analysis of nine pirethroid pesticides in water samples by the combination of hollow fibre-based liquid-phase microextraction (HF-LPME) and gas chromatography-mass spectrometry (GC/MS). For the developed method, nine pirethroid pesticides (e...

This paper reports an alternative analytical methodology for the determination of chloride and sulphate impurities in hexafluorosilicic acid, FSA, using capillary zone electrophoresis. The influence of different electrophoretic and matrix variables on electrophoretic response was studied. Samples were injected hydrodynamically onto a fused silica c...

A high-performance liquid chromatographic method with photometric detection has been developed for the determination of five angiotensin II receptor antagonists (ARA II): Losartan, Irbesartan, Valsartan, and Candesartan cilexetil and its metabolite Candesartan M1. Reversedphase chromatography was performed at room temperature on a μBondapak C18 col...

The operation of an activated sludge wastewater treatment plant (WWTP) was assessed by determining the removal efficiency of treatment processes. For that purpose, different physicochemical and microbiological parameters, including total, active and culturable bacteria, were measured along a year. Values of both physicochemical and microbiological...

This paper reports an LC-MS/MS method with positive electrospray ionization for the screening of commonly prescribed cardiovascular drugs in human plasma, including compounds with antihypertensive (57), antidiabetic (12), hypolipemiant (5), anticoagulant (2) and platelet anti-aggregation (2) effects. Sample treatment consisted of a simple protein p...

In this paper, the stability at storage conditions of inclusion complexes formed by the biocides: the bendiocarb carbamate, nicotinoid and pyrethroid families, the pyperonyl butoxide synergist and the tebuconazole fungicide, with β-cyclodextrin (CD) were studied. These complexes, in solid state and aqueous suspension, were exposed to normal atmosph...

A simple, fast and validated method is reported for the simultaneous analysis, in human plasma, of several drugs usually combined in cardiovascular therapy (atenolol, bisoprolol, hydrochlorothiazide, chlorthalidone, salicylic acid, enalapril and its active metabolite enalaprilat, valsartan and fluvastatin) using high performance liquid chromatograp...

The hydrolytic reaction of Triazolam in acidic solution at room temperature was studied spectrophotometrically. The reversible azomethine bond cleavage reaction of Triazolam took place and an open-ring compound was in equilibrium with a closed-ring compound. Kinetic studies indicate that the hydrolysis reaction is first order with respect to proton...

The proton NMR and the high-resolution electron impact mass spectra of alprazolam and triazolam, two new triazolo [4,3-a]-[1,4]-benzodiazepines were studied.

This work reviews the different analytical methods that have been proposed in the field of forensic dating of inks from different modern writing instruments. The reported works have been classified according to the writing instrument studied and the ink component analyzed in relation to aging. The study, done chronologically, shows the advances exp...

Ultra-performance liquid chromatography (UPLC) was investigated as a faster alternative to high-performance liquid chromatography (HPLC) for the simultaneous analysis of drugs usually prescribed in cardiovascular therapy. Upon a previously developed and validated solid phase extraction (SPE)-HPLC-photodiode array (PDA)-fluorescence (FLR) method, se...

The effects of deltamethrin, in the presence and absence of nitrate, on soil microbial activity (as reflected by the rates of soil microbial basal respiration, denitrification, and methanogenesis) were studied in a riparian wetland soil under both aerobic and anaerobic conditions. A microcosm study was carried out with soil collected from the vicin...

This paper reports the chemometrical optimization and the validation of a quantitative high performance liquid chromatography-photodiode array-fluorescence (HPLC-PDA-Fluo) method for the simultaneous analysis, in human plasma, of drugs usually combined in cardiovascular therapy. Separation of chlorthalidone (CLTD), valsartan (VAL), valsartan-M1 (VA...

In this work, an SPE-HPLC method coupled to photodiode array detection was validated in human urine matrix, in order to monitor four antihypertensive angiotensin II receptor antagonist drugs in patients under cardiovascular treatment. For that purpose, experimental design was used. Quantitation was accomplished by the internal standard method. The...

For the quantitation of angiotensin II receptor antagonists (ARA-II) in human plasma, a method using liquid-chromatography (LC)-electrospray ionization tandem mass spectrometry (MS/MS) has been developed with respect to simple sample clean-up and investigation of ion suppression effects. For sample preparation, protein precipitation using zinc sulp...

The optimisation of a solid phase extraction procedure involves several variables whose influence has been widely studied. However, in most cases, only process variables are taken into account. In this work, the influence of those process variables together with the fact of using mixtures of solvents during the elution step of the solid phase extra...

A simple and fast method for the simultaneous determination of the antihypertensive drug Valsartan and its metabolite in human plasma has been validated. The proposed method deals with SPE, followed by an HPLC separation coupled with fluorimetric and photometric detection. The optimization of the SPE-HPLC method was achieved by an experimental desi...

Candesartan cilexetil is an angiotensin receptor antagonist widely used in the treatment of high blood pressure. This prodrug is metabolised into candesartan, which blocks the receptors AT1 for angiotensin II decreasing the blood pressure levels. During the development of a solid phase extraction procedure for the chromatographic determination of e...

The identification of organic colorants used in artistic paintings is an important information source for reconstructing the working techniques found in a particular work and for defining a programme for the restoration and conservation of the painting. In this work, sodium dodecyl sulfate (SDS) was used as a surfactant in micellar electrokinetic c...

A rapid and simple high performance liquid chromatographic (HPLC) method with amperometric detection has been developed for the quantitative determination of oxprenolol in human urine and pharmaceuticals. The chromatographic method was performed at (25 ± 0.2)°C on a reversed-phase column (Supelcosil ABZ + Plus) with a mobile phase of acetonitrile-w...

A chemometric approach was applied for the optimization of the extraction and separation of the antihypertensive drug valsartan and its metabolite valeryl-4-hydroxy-valsartan from human plasma samples. Due to the high number of experimental and response variables to be studied, fractional factorial design (FFD) and central composite design (CCD) we...

Phenolic resins formed from the condensation of phenol with formaldehyde find a wide range of applications in industry. The highly polar structure and thermal instability of hydroxymethol phenols makes HPLC a suitable method for the separation of low-molecular-weight prepolymers up to a molecular weight of 1000. The aim of this work was to develop...

In this work, a solid phase extraction-reversed phase high performance liquid chromatographic (SPE-RP-HPLC) method with photometric detection for monitoring the antihypertensive drug eprosartan has been validated in order to assure good quantitation of eprosartan in plasma samples obtained from patients under cardiovascular treatment. This analytic...

A chemometric approach was applied for the optimization of the extraction and separation of the antihypertensive drug eprosartan from human plasma samples. MultiSimplex program was used to optimize the HPLC-UV method due to the number of experimental and response variables to be studied. The measured responses were the corrected area, the separatio...

1,4-Dihydropyridines calcium channel antagonists (1,4-DHP CCAs) are photolabile and the products of their photodecomposition have no pharmaceutical activity. In our previous work we have presented a screening procedure for eleven 1,4-DHPs in plasma by LC-MS-MS using multiple reaction motoring. The laboratory process includes preparation and storage...

A liquid-liquid extraction method using diethyl ether as organic solvent was optimized simultaneously for five 1,4-dihydropyridines (amlodipine, nitrendipine, felodipine, lacidipine and lercanidipine) belonging to the group of calcium channel blockers. Some experimental tools such as a full factorial design, a central composite design and the Multi...

A high-performance liquid chromatographic method with diode array detection has been developed and optimized for the separation of five calcium channel blockers belonging to the 1,4-dihydropyridine subgroup (nifedipine and related drugs). The possibility of the simultaneous drug analysis allows a decrease of time during the assay as well as a savin...

A high-performance liquid chromatographic method with diode array detection has been developed for the determination of five 1,4-dihydropyridines: amlodipine, nitrendipine, felodipine, lacidipine and lercanidipine. A fractional design and a central composite design were used. The factors considered in the optimisation process were: percentage of or...

A sensitive and specific liquid chromatography-tandem mass spectrometric method has been developed and validated for the quantification of the five 1,4-dihydropyridine calcium channel antagonists amlodipine, lercanidipine, nitrendipine, felodipine, and lacidipine in human plasma. Sample preparation involved solid-phase extraction on RP-C18 cartridg...

The pyrethroid lambda-cyhalothrin is a common insecticide which is widespread in the environment. A study of the electrochemical reduction of the pesticide on a hanging mercury drop electrode (HMDE) was performed as basis for the development of a sensitive analytical method for determination of lambda-cyhalothrin in natural samples. Two electrochem...

A capillary electrophoretic method was optimised for the separation and determination of iodide used as artificial tracer in hydrology. The influence of the buffer concentration and pH, electroosmotic flow modifier concentration (cetyltrimethylammonium bromide (CTAB)), the injection time and voltage applied, on the electrophoretic separation was st...

A high-performance liquid chromatographic method with electrochemical detection was developed for the simultaneous determination of five 1,4-dihydropyridines: amlodipine, nitrendipine, felodipine, lacidipine and lercanidipine. These drugs are widely used in the treatment of hypertension, angina pectoris and the therapy of cerebrovascular spasms of...

Experimental design methodologies are applied to the development of a capillary zone electrophoretic method for the separation of the angiotensin-converting enzyme inhibitor enalapril and its derivative enalaprilat and the diuretics xipamide and hydrochlorothiazide. The effects of pH, buffer concentration, proportion of boric acid in the mixed bori...