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1.
Plants (Basel) ; 11(12)2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35736745

RESUMO

The application of biostimulants appears to be an environmentally friendly, innovative, and sustainable agronomical tool to mitigate the negative effects induced by adverse climatology in traditional grape-growing regions such as La Rioja (Spain). However, their mechanism of action in grapevines is still unclear. We evaluated how commercial substances (two from Ascophyllum nodosum extraction and one amino acids-based biostimulant) and the non-proteinogenic amino acid ß-aminobutyric acid (BABA) affect the quality and quantity of musts and grapes in Vitis vinifera L. cv. Tempranillo from a semi-arid region of La Rioja during two seasons. We hypothesized an enhancement in organic metabolites in berries and leaves in response to these treatments, changing the organoleptic characteristics of the final products. The treatments altered the primary metabolites such as carbohydrates, organic acids (AcOrg), and free amino acids, first in the leaves as the effect of the foliar application and second in grapes and musts. As the main result, the biostimulant efficiency depended on the climatology and vineyard location to improve the final yield. Whereas biostimulant application enhanced the yield in 2018 (less dry year), it did not help production in 2019 (dry year). BABA was the most efficient biostimulant, enhancing plant production. Regarding yield quality, the biostimulant application improved the musts mainly by enhancing the fumaric acid content and by reducing carbohydrates, except in BABA-treated plants, where they were accumulated. These results corroborate biostimulants as an exciting approach in wine production, especially for improving wine quality.

2.
Rev. Fund. Educ. Méd. (Ed. impr.) ; 24(1): 36-41, ene.-feb. 2021. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-202421

RESUMO

INTRODUCCIÓN: La transferencia del conocimiento a la sociedad es una de las funciones importantes de la Universidad, lo que implica el uso de un lenguaje y unos medios adecuados hacia los diferentes colectivos de la sociedad, atendiendo a grupos de edad y situaciones socioeconómicas diversas. MATERIALES Y MÉTODOS: A través de las competencias transversales de cada grado, competencias genéricas que se relacionan con la puesta en práctica de una forma integrada de aptitudes, conocimientos y valores adquiridos, se ha realizado este proyecto de innovación docente con alumnado de la Universidad del País Vasco/Euskal Herriko Unibertsitatea. En él se han trabajado las habilidades del alumnado en el uso de diferentes registros de comunicación oral y escritura según la audiencia hacia la que se dirigen. Este trabajo se ha realizado dentro de un equipo multidisciplinar, de forma que el alumnado ha podido conocer y afrontar problemas de salud que requieren una actuación conjunta con otros profesionales del ámbito sanitario y científico. RESULTADOS Y CONCLUSIÓN: Esta interacción entre alumnado de diferentes grados ha permitido su enriquecimiento, proporcionándoles una visión más amplia de lo que pueden aportar los diferentes profesionales frente al mismo problema o reto. Desde este proyecto se ha planteado, a través de metodologías activas, favorecer la interacción entre los futuros profesionales de diferentes disciplinas y concienciar de la importancia de la transmisión de conocimiento a la sociedad, creando redes que contribuyan a la innovación y transferencia


INTRODUCTION: The transfer of knowledge to society is one of the important functions of the university, which implies the use of an appropriate language and means towards the different groups of society, attending to age groups and diverse socio-economic situations. MATERIALS AND METHODS: Through the transversal competences of each Degree, generic competences that are related to the implementation of an integrated form of acquired skills, knowledge and values, this teaching innovation project has been carried out with students from the University of The Basque Country (UPV / EHU). Thus, the student's abilities in the use of different oral and written communication registers according to the target audience have been studied. This work has been carried out within a multidisciplinary team, in such a way that the student has been able to know and face health problems that require joint action with other professionals in the health and scientific field. RESULTS AND CONCLUSION: This interaction among students of different degrees has allowed their enrichment, providing them with a broader vision of what different professionals can contribute to the same problem or challenge. From this project, it has been proposed, through active methodologies, to promote interaction between future professionals from different disciplines, and to raise awareness of the importance of the transmission of knowledge to society, creating networks that contribute to innovation and transfer


Assuntos
Humanos , Universidades/tendências , Disseminação de Informação , Difusão de Inovações , Comunicação Acadêmica/tendências , Acesso à Informação , Relações Comunidade-Instituição/tendências , Comunicação Interdisciplinar , Inovação Organizacional , Estudantes
3.
J Forensic Sci ; 65(4): 1094-1101, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31943223

RESUMO

Currently, aluminum stub with carbon adhesive devices are used to collect inorganic gunshot residues (GSR) from the hands of a shooter. In an ideal shooting case, the gunshot particles do not persist for more than 2 h in the hands of the shooter, provided that the hands have not been washed. However, for forensic analysis and inference, the extended persistence of GSR would be desirable. This study investigates a novel GSR sampling and detection protocol. Sampling was performed in the nostrils using swab devices impregnated in ethylenediaminetetraacetic acid (EDTA). The GSRs persisted for longer periods in nasal mucus than on the hands, and particles were detected 6 h after shooting occurred. The analytical determination was conducted by scanning laser ablation-inductively coupled plasma-mass spectrometry (SLA-ICPMS) which enable the identification of the number of particles and their elemental composition. Seventeen isotope signals corresponding to 13 C, 205 Tl and 15 analytes that are usually associated with the composition of GSR residues were monitored: 27 Al, 29 Si, 31 P, 33 S, 35 Cl, 39 K, 44 Ca, 57 Fe, 60 Ni, 63 Cu, 66 Zn, 118 Sn, 121 Sb, 137 Ba, and 208 Pb. The SLA technique enabled the reduction of the swab analysis time to 40 min. The effectiveness of this methodology was evaluated with two types of firearms: a pistol and a shotgun. The results indicated that the methodology proposed for the analysis of the nasal GSR was effective and that it can improve or complement the forensic analyses and inferences presented in a court.


Assuntos
Antimônio/análise , Bário/análise , Balística Forense/métodos , Chumbo/análise , Mucosa Nasal/química , Ácido Edético , Mãos , Humanos , Isótopos , Lasers de Estado Sólido , Espectrometria de Massas/métodos , Pele/química , Manejo de Espécimes , Ferimentos por Arma de Fogo
4.
Sci Total Environ ; 687: 319-329, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31207521

RESUMO

Systematic fungicides treatments in vine-growing European ecosystems have been conducted for decades. The goal of this study was to determine the mobility and persistence of 20 fungicides used in two viticultural zones in Atlantic and Mediterranean climates, from the moment of their application until their distribution throughout different compartments of the ecosystem: soil, water, grapes, musts and wines. This study also sought to obtain valuable information to reduce the usage of these products without affecting the health of the vines. For this purpose, different phytosanitary treatments were applied, using dosing criteria based on data provided by meteorological stations, degree-day accumulation, phenological state, and growers' criteria. The observed differences between studied geographical areas were not significant with regard to chemical accumulation in the soil and water; however, they were significantly different regarding to grapes, musts, and wines.


Assuntos
Agricultura/métodos , Ecossistema , Meio Ambiente , Fungicidas Industriais/análise , Vinho , Vitis
5.
J Sep Sci ; 40(23): 4549-4562, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28988466

RESUMO

The characterization of ancient lipids from prehistoric sediments (fumiers) located in a rock-selter has been possible after the optimization of an analytical method based on the microwave-assisted extraction and solid-phase extraction clean-up step and a final derivatization step followed by gas chromatography with mass spectrometry. Eight sterols and two bile acids were detected just in the partially burned and unburned layers of the fumiers (animal organic residues deriving from manure/dung). The relationship between some of these compounds can be used to distinguish the biogenic origin of the samples, concluding that these strata (from Early Neolithic to Late Chalcolithic/Early Bronze Age) can be classified as ruminant residues. Three main periods of activity are observed over a period of 2000 years: one from 3990 ± 40 before present (4530-4410 calibrated before present) to 4100 ± 40 before present (4820-4750/4730-4510/4470-4450 calibrated before present), the second from 4470 ± 40 before present (5300-4970 calibrated before present) to 5490 ± 30 before present (6310-6275/6230-6220 calibrated before present) and the third from 5880 ± 30 before present (6775-6765/6750-6645 calibrated before present) to 6010 ± 30 before present (6940-6780/6765-6755 calibrated before present). Chemical data obtained are in concordance with the previous results obtained in the area.

6.
Sci Total Environ ; 578: 392-398, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-27838055

RESUMO

The uptake calibration of three passive samplers, stir-bars, MESCO/stir-bars and polyethersulfone tubes (PESt), was assessed in seawater at different salinities for 17 organic compounds including organochlorine compounds, pesticides, phthalates, musk fragrances and triclosan. The calibration procedure was accomplished by exposing the samplers to a continuous flow of fortified seawater for up to 14days under laboratory conditions. Prior to the exposure, stir-bars and MESCO/stir-bars were loaded with a known amount of deuterated PAH mixture as performance reference compounds (PRC). For most of the studied compounds, the sampling rates (Rs, mL·day-1) were determined for each sampler at two salinities (15 and 30‰) and two nominal concentrations (25 and 50ng·L-1). Among the tested devices, though PES can be an outstanding cheap alternative to other passive samplers, naked or free stir-bars provided the best results in terms of uptake rates (i.e., the Rs values ranged from 30 to 350mL·day-1). Regarding the variation of the salinity, the Rs values obtained with naked stir-bars were statistically comparable in the full range of salinities (0-30‰) but the values obtained with MESCO/stir-bars and PESt were salinity dependent. Consequently, only stir-bars assured the required robustness to be used as passive samplers in intertidal estuarine environments. Finally, the stir-bars were applied to estimate the time-weighted average concentration of some of those contaminants in the feeding seawater of the experimental aquaria at the Plentzia Marine Station (Basque Country) and low levels of musks fragrances (0.1-0.2ng·L-1) were estimated.


Assuntos
Dimetilpolisiloxanos/análise , Monitoramento Ambiental , Estuários , Polímeros/análise , Sulfonas/análise , Poluentes Químicos da Água/análise , Compostos Orgânicos , Espanha
7.
Anal Bioanal Chem ; 408(21): 5689-5700, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27342793

RESUMO

This study describes a new method for the simultaneous extraction of several endocrine disrupting compounds, including alkylphenols (APs), estrogen, bisphenol-A (BPA) and one phthalate metabolite (mono-2-ethylhexyl ester, MEHP) in fish liver, brain, and muscle. Parameters affecting the extraction (extraction solvent and temperature) and the clean-up (dispersive phase nature and amount) steps were evaluated. The extraction was performed by means of focused ultrasound solid-liquid extraction (FUSLE) using 10 mL of n-hexane:acetone (50:50, v/v) for 5 min at ~0 °C, and the clean-up was done by means of dispersive solid phase extraction (dSPE) using 100 mg of ENVI-CARB and 100 mg of MgSO4 for the cleaning of brain and muscle extracts together with 100 mg of PSA in the case of liver extracts. Good apparent recoveries were obtained in the case of liver (62-132 %), brain (66-120 %), and muscle (74-129 %), relative standard deviation (RSD%) was always below 26 %, and the method detection limits (MDLs) were at low ng/g level. The developed method was applied to fish captured in Urdaibai estuary (Bay of Biscay) in December 2015, and the concentrations obtained were in the range MDL-1115 ng/g in brain, MDL-962 ng/g in muscle, and MDL-672 ng/g in liver. In general, the highest concentrations were measured in liver, followed by brain and muscle. In addition, diethylstilbestrol was only detected in fish brain. Graphical Abstract MS method scheme for the/MS method scheme for the determination of EDCs in fish liver, brain and muscle.


Assuntos
Disruptores Endócrinos/análise , Peixes/metabolismo , Extração em Fase Sólida/métodos , Poluentes Químicos da Água/análise , Animais , Compostos Benzidrílicos/análise , Encéfalo/metabolismo , Estrogênios/análise , Limite de Detecção , Fígado/metabolismo , Músculos/metabolismo , Fenóis/análise , Ácidos Ftálicos/análise , Sonicação/métodos , Espectrometria de Massas em Tandem/métodos
8.
J Food Sci ; 81(4): C867-73, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26925555

RESUMO

Seven monoterpenes in 4 aromatic plants (sage, cardamom, lavender, and rosemary) were quantified in liquid extracts and directly in solid samples by means of dynamic headspace-gas chromatography-mass spectrometry (DHS-GC-MS) and multiple headspace extraction-gas chromatography-mass spectrometry (MHSE), respectively. The monoterpenes were 1st extracted by means of supercritical fluid extraction (SFE) and analyzed by an optimized DHS-GC-MS. The optimization of the dynamic extraction step and the desorption/cryo-focusing step were tackled independently by experimental design assays. The best working conditions were set at 30 °C for the incubation temperature, 5 min of incubation time, and 40 mL of purge volume for the dynamic extraction step of these bioactive molecules. The conditions of the desorption/cryo-trapping step from the Tenax TA trap were set at follows: the temperature was increased from 30 to 300 °C at 150 °C/min, although the cryo-trapping was maintained at -70 °C. In order to estimate the efficiency of the SFE process, the analysis of monoterpenes in the 4 aromatic plants was directly carried out by means of MHSE because it did not require any sample preparation. Good linearity (r2) > 0.99) and reproducibility (relative standard deviation % <12) was obtained for solid and liquid quantification approaches, in the ranges of 0.5 to 200 ng and 10 to 500 ng/mL, respectively. The developed methods were applied to analyze the concentration of 7 monoterpenes in aromatic plants obtaining concentrations in the range of 2 to 6000 ng/g and 0.25 to 110 µg/mg, respectively.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Magnoliopsida/química , Monoterpenos/análise , Óleos Voláteis/análise , Extratos Vegetais/química , Cromatografia com Fluido Supercrítico/métodos , Elettaria/química , Lavandula/química , Reprodutibilidade dos Testes , Rosmarinus/química , Salvia/química , Temperatura
9.
Anal Bioanal Chem ; 408(12): 3165-75, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26892638

RESUMO

The uptake calibration of more than 12 non-polar organic contaminants by 3 polymeric materials is shown: bare polydimetilsiloxane (PDMS, stir-bars), polyethersulfone tubes and membranes (PES) and polyoxymethylene membranes (POM), both in their free form and membrane-enclosed sorptive coating (MESCO). The calibration process was carried out exposing the samplers to a continuous flow of contaminated water at 100 ng mL(-1) for up to 28 days, and, consequently, the sampling rates (Rs, mL day(-1)) of several organic microcontaminants were provided for the first time. In situ Rs values were also determined disposing the samplers in the effluent of a wastewater treatment plant. Finally, these passive samplers were applied to monitor the effluents of two wastewater treatment plants. This application lead to the confirmation of the presence of galaxolide, tonalide and 4-tert-octylphenol at high ng mL(-1) levels, as well as the identification of compounds like some phthalates and alkylphenols at levels below the detection limits for active sampling methods.

10.
Food Chem ; 190: 614-621, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26213018

RESUMO

Wine production wastes are an interesting source of natural polyphenols. In this work, wine wastes extracts were encapsulated through vibration nozzle microencapsulation using sodium alginate as polymer and calcium chloride as hardening reagent. An experimental design approach was used to obtain calcium-alginate microbeads with high polyphenol content and good morphological features. In this way, the effect of pressure, frequency, voltage and the distance to the gelling bath were optimized for two nozzles of 150 and 300 µm. Long-term stability of the microbeads was studied for 6 months taking into account different storage conditions: temperatures (4 °C and room temperature), in darkness and in presence of light, and the addition of chitosan to the gelling bath. Encapsulated polyphenols were found to be much more stable compared to free polyphenols regardless the encapsulation procedure and storage conditions. Moreover, slightly lower degradation rates were obtained when chitosan was added to the gelling bath.


Assuntos
Catequina/química , Composição de Medicamentos/métodos , Polifenóis/química , Vitis/química , Vinho/análise , Polifenóis/análise
11.
Bioanalysis ; 7(17): 2211-25, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26395171

RESUMO

Dispersive liquid-liquid microextraction (DLLME) is a recent microextraction technique that was first developed by Rezaee and co-workers in 2006. It allows the simultaneous extraction and preconcentration of analytes into a micro-volume of extracting solvent based on a ternary solvent system involving an aqueous phase, a nonpolar water immiscible high-density solvent that acts as extraction phase, and a disperser solvent, which is often polar and water miscible. This article presents an overview of DLLME applications in the analysis of biological samples (e.g., plasma and urine). Aside from the classical DLLME applications using high density extraction solvents, recent advances in the use of low density solvents and ionic liquids are also discussed. Although most of the applications deal with the analysis of organic target compounds, a few applications on the bioanalysis of inorganic substances are also included.


Assuntos
Testes de Química Clínica/métodos , Microextração em Fase Líquida/métodos , Humanos , Solventes/química
12.
Anal Bioanal Chem ; 407(24): 7413-23, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26229028

RESUMO

This study describes a new method for the simultaneous extraction and enzymatic hydrolysis of alkylphenols, estrogens, bisphenol-A and phthalate metabolite (mono-2-ethylhexyl ester, MEHP) in fish bile using polyethersulfone (PES) polymer as sorptive material. Parameters affecting the hydrolysis (enzyme amount) and extraction (nature of polymeric material, PES desorption solvent nature and time, PES amount and time profile) were optimised. The optimum conditions were fixed as: 5 PES tubes (1.5 cm length × 0.7 mm o.d.) were added to a vessel with 100 µL of sample, 800 µL of ultrapure water, 1.5 mL phosphate buffer (0.1 mol L(-1), pH 6) and 200 µL of ß-glucuronidase (1000 U mL(-1)) enzyme and the mixture was stirred at 37 °C and 550 rpm for 3 h. Quantitative results were obtained after desorption of PES material using 500 µL of ethyl acetate. The extracts were reconstituted in 250 µL of methanol and analysed by liquid chromatography-tandem mass spectrometry, obtaining apparent recoveries in the range of 73-134 % using deuterated compounds surrogates corrections. Relative standard deviations below 27 % were obtained for all target analytes and the method detection limits (MDLs) were in low nanograms per mililliter level for all the studied compounds, except in the case of MEHP which was detected at higher concentration levels (ng µL(-1)) in bile samples that do not allow its MDL determination. Bisphenol A (MDL-10.8 ng mL(-1)), diethylstilbestrol (MDL-1.4 ng mL(-1)) and MEHP (975-2604 ng mL(-1)) were detected in grey mullets captured nearby the wastewater treatment plant of Gernika (Biosphere Reserve of Urdaibai).


Assuntos
Bile/metabolismo , Disruptores Endócrinos/metabolismo , Glucuronidase/metabolismo , Polímeros/química , Smegmamorpha/metabolismo , Sulfonas/química , Animais , Cromatografia Líquida , Disruptores Endócrinos/isolamento & purificação , Espectrometria de Massas em Tandem
13.
Sci Total Environ ; 536: 261-267, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26218565

RESUMO

This work describes a new methodology for the simultaneous determination of a large variety of emerging and persistent organic compounds and some of their metabolites in fish bile samples. The target compounds were musk fragrances, alkyl phenols, hormones, pesticides, phthalate esters and bisphenol-A, all of them with a known endocrine disrupting effect. To achieve the determination these three steps were optimized: i) an enzymatic hydrolysis of the metabolites to render the unconjugated compounds; ii) the solid phase extraction of the target analytes (Plexa cartridges 200-mg); and, iii) a clean-up of the extracts (Florisil cartridges 1-g). The samples were analyzed by gas-chromatography-mass spectrometry (GC-MS), though the polar fraction required a previous derivatization with O-bis (trimethylsilyl) trifluoroacetamide. Good apparent recoveries (63-122%), repeatability (<20%) and limits of detection (LODs) ranging between 0.04 and 459 ng/mL were obtained. This method was applied to the analysis of the target analytes in bile samples of thicklip grey mullets (Chelon labrosus) from five different populations of the Basque Coast (South East Bay of Biscay) during the period of May-June 2012. The target analytes were found at concentrations ranging from

Assuntos
Bile/química , Disruptores Endócrinos/análise , Peixes/metabolismo , Poluentes Químicos da Água/análise , Animais , Compostos Benzidrílicos/análise , Compostos Benzidrílicos/metabolismo , Bile/metabolismo , Disruptores Endócrinos/metabolismo , Monitoramento Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Fenóis/análise , Fenóis/metabolismo , Ácidos Ftálicos/análise , Ácidos Ftálicos/metabolismo , Smegmamorpha , Extração em Fase Sólida , Poluentes Químicos da Água/metabolismo
14.
J Food Sci ; 80(1): E101-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25471637

RESUMO

In this study, supercritical fluid extraction has been successfully applied to a sequential fractionation of fatty acids and polyphenols from wine wastes (2 different vitis vinifera grapes). To this aim, in a 1st step just fatty acids were extracted and in a 2nd one the polyphenols. The variables that affected to the extraction efficiency were separately optimized in both steps following an experimental design approach. The effect of extraction temperature flow, pressure, and time were thoroughly evaluated for the extraction of fatty acids, whereas the addition of methanol was also considered in the case of the polyphenols extraction. A quantitative extraction with high efficiency was achieved at a very short time and low temperatures. Concerning quantification, fatty acids were determined by means of gas chromatography coupled to mass spectrometry after a derivatization step, whereas the polyphenols were analyzed by means of high performance liquid chromatography coupled to tandem mass spectrometry and the Folin-Ciocalteu method.


Assuntos
Cromatografia com Fluido Supercrítico , Ácidos Graxos/análise , Polifenóis/análise , Vitis/química , Fracionamento Químico , Cromatografia Líquida de Alta Pressão , Manipulação de Alimentos , Cromatografia Gasosa-Espectrometria de Massas , Resíduos Industriais/análise , Metanol/química , Espectrometria de Massas em Tandem , Vinho/análise
15.
Environ Sci Pollut Res Int ; 21(20): 11867-83, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24424482

RESUMO

Among the different organic pollutants, persistent organic pollutants and emerging organic contaminants (EOCs) are of particular concern due to their potentially dangerous effects on the ecosystems and on human health. In the framework of the analysis of some of these organic pollutants in water samples, sorptive extraction devices have proven to be adequate for their monitoring. The efficiency of four commercially available and low-cost polymeric materials [polypropylene, poly(ethylene terephthalate), Raffia, and polyethersulfone (PES)] for the simultaneous extraction of 16 organic compounds from five different families from environmental water samples was evaluated in this work. Firstly, the homogeneity of the sorbent materials was confirmed by means of Raman spectroscopy. After the optimization of the parameters affecting the extraction and the liquid desorption steps, it was found that PES showed the largest efficiencies for slightly polar analytes and, to a lesser extent, for nonpolar analytes. Additionally, Raffia rendered good extraction efficiencies for nonpolar compounds. Thus sorptive extraction methods followed by large volume injection-programmable temperature vaporizer-gas chromatography-mass spectrometry were validated using PES and Raffia as sorbent materials. The validation of the method provided good linearity (0.978 < r (2) < 0.999 for PES and 0.977 < r (2) < 0.999 for Raffia), adequate repeatability (below 19 % and 14 % for PES and Raffia, respectively), and low method detection limits (low ng · l(-1) level). Finally, these materials were applied to the analysis of contaminants in environmental water samples.


Assuntos
Meio Ambiente , Compostos Orgânicos/análise , Polímeros/química , Microextração em Fase Sólida/métodos , Poluentes Químicos da Água/análise , Adsorção , Estuários , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Polietilenotereftalatos/química , Polipropilenos/química , Análise Espectral Raman , Sulfonas/química , Temperatura , Fatores de Tempo , Águas Residuárias/química
16.
Talanta ; 119: 53-9, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24401384

RESUMO

Focused-ultrasound solid-liquid extraction was developed for the extraction of polybrominated diphenyl ethers in vegetables and amended soil. Firstly, solid-phase extraction clean-up using 2g and 5 g of Florisil and 2-g silica cartridges were evaluated and elution profile was also optimised. Similar recoveries were obtained for most compounds while better recoveries were obtained for 5-g Florisil in the case of the heavier PBDEs. FUSLE extraction time (2 min) guaranteed quantitative extraction of the target analytes in the four studied matrices (69-130%). Method detection limit values were in the range of 1-5 ng g(-1) for splitless injection in a gas chromatograph coupled to a mass spectrometer and no significant improvement was obtained for large volume injection. Relative standard deviation values were between 1% and 30%. Recoveries obtained using FUSLE were compared with those obtained with microwave assisted extraction and the developed method was also applied to a certify reference material of polybrominated diphenyl ethers and polychlorinared biphenyls in sediment. Similar values were obtained in the case of carrot and pepper matrices (77-130% for FUSLE and 77-112% for MAE). However, MAE provided extraction recoveries higher than 100% for most of the BDE congeners in lettuce and amended soil.


Assuntos
Éteres Difenil Halogenados/análise , Poluentes do Solo/análise , Ultrassom , Verduras/química , Cromatografia Gasosa-Espectrometria de Massas , Éteres Difenil Halogenados/isolamento & purificação , Limite de Detecção , Extração Líquido-Líquido , Micro-Ondas , Padrões de Referência , Poluentes do Solo/isolamento & purificação , Extração em Fase Sólida
17.
Talanta ; 117: 471-82, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24209370

RESUMO

In this study a priority organic pollutants usually found in environmental water samples were considered to accomplish two extraction and analysis approaches. Among those compounds organochlorine compounds, pesticides, phthalates, phenols and residues of pharmaceutical and personal care products were included. The extraction and analysis steps were based on silicone rod extraction (SR) followed by liquid desorption in combination with large volume injection-programmable temperature vaporiser (LVI-PTV) and gas chromatography-mass spectrometry (GC-MS). Variables affecting the analytical response as a function of the programmable temperature vaporiser (PTV) parameters were firstly optimised following an experimental design approach. The SR extraction and desorption conditions were assessed afterwards, including matrix modification, time extraction, and stripping solvent composition. Subsequently, the possibility of performing membrane enclosed sorptive coating extraction (MESCO) as a modified extraction approach was also evaluated. The optimised method showed low method detection limits (3-35 ng L(-1)), acceptable accuracy (78-114%) and precision values (<13%) for most of the studied analytes regardless of the aqueous matrix. Finally, the developed approach was successfully applied to the determination of target analytes in aqueous environmental matrices including estuarine and wastewater samples.


Assuntos
Hidrocarbonetos Clorados/análise , Praguicidas/análise , Fenóis/análise , Ácidos Ftálicos/análise , Silicones/isolamento & purificação , Águas Residuárias/química , Poluentes Químicos da Água/análise , Adsorção , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Limite de Detecção , Extração em Fase Sólida , Temperatura , Volatilização
18.
Talanta ; 88: 145-51, 2012 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-22265480

RESUMO

Comprehensive two-dimensional gas-chromatography (GC×GC) is a great tool to explore complex essential oils. In this work the different terpene composition of the aroma fraction of rosemary and oregano were studied. The present investigation is based on the optimization of the comprehensive two-dimensional gas-chromatographic method through the use of experimental designs and Multisimplex, and studying the modulation period, discharge-time and first and second column flows. Making use of a non-polar column (HP-5) in the first dimension and an intermediate one (DB-17) in the second dimension, we concluded that 1.42s, 0.12s, 1.23 mL/min and 17.55 mL/min were our optimum values, respectively. The use of a highly polar phase in the second dimension did not make any significant improvement. Finally, aroma quantification of the studied plants was performed by means of the optimum method achieved and functional groups "bands" were studied. The essential oil concentration ranges obtained were, 0.04-6.6 µg/g for rosemary extracts and 0.04-0.5 µg/g for oregano extracts.


Assuntos
Óleos Voláteis/análise , Origanum/química , Rosmarinus/química , Terpenos/análise , Calibragem , Cromatografia Gasosa-Espectrometria de Massas/métodos , Plantas Medicinais/química
19.
Talanta ; 83(2): 605-12, 2010 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-21111181

RESUMO

The analysis of hydrocarbons in chert rocks provides a worthwhile source of information regarding the geochemical features of a depositional setting. Since the typical analytical procedure requires long Soxhlet extractions and the use of large quantities of sample (30-50 g), in this work we have optimised the focused ultrasound extraction (FUSE) and the microwave-assisted extraction (MAE) to make available a less severe procedure. In both cases a full experimental design including solvent mixture composition (Dichloromethane/Hexane/Acetone) and process variables (sonication time and cycles, and extraction temperature and time) by means of D-optimal designs. In the extracted fractions hydrocarbons (C(16)-C(40)) were analysed by gas-chromatography-mass spectrometry. In the case of FUSE the process variables were the most sensitive variables and the optimum conditions were defined at 60:40 DCM/Hex mixture and a sonication time of 30 min and 9 cycles. In the case of MAE all the variables shown a significant effect on the extraction yield and the most adequate conditions (60:30:10 DCM/Hex/Ace mixture and an irradiation time of 15 min at 110 °C) were established from the analysis of the response surface. Both methods were systematically applied with different chert samples collected in Cucho (Trebiño County, Burgos, Spain) and we were able to assure quantitative extractions (>85%) in the first extraction. Additionally, from the distribution patterns of n-alkanes obtained in the different chert samples (nodular chert, laminar chert and massive-brechoid chert) collected in Cucho, we were able to distinguish different origins and diagenetic history.


Assuntos
Geologia/métodos , Micro-Ondas , Alcenos/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Sedimentos Geológicos/química , Hidrocarbonetos/química , Solventes/química , Temperatura , Ultrassom , Ultrassonografia/métodos
20.
Anal Bioanal Chem ; 398(5): 2307-14, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20835815

RESUMO

According to the European Water Framework Directive (WFD), alkylphenols, such as octylphenols and nonylphenols, and 17ß-oestradiol are considered as priority or emerging pollutants, respectively, mainly due to their possible properties as endocrine-disrupting compounds (EDCs). EDCs are accumulated in liver, fat, kidney and bile in the glucuronide form. In order to determine the concentration of these compounds in bile, an enzymatic hydrolysis step is necessary. This step is usually long (~16 h), and in this sense, ultrasound probes were studied as a possible alternative energy source to accelerate this process. Enzymatic hydrolysis was reduced to 20 min using an ultrasound probe at one cycle and 10% of amplitude. For validation of analytical procedure, nonylphenol glucuronide (4NP-G), 4-tert-octylphenol glucuronide (4tOP-G) and 4-n-octylphenol glucuronide (4nOP-G) were synthesised while 17ß-oestradiol glucuronide (E2-G) was commercially available. Bile from thick-lip grey mullets (Chelon labrosus) was spiked with known amounts of 4NP-G, 4tOP-G, 4nOP-G and E2-G and submitted to the optimised procedure. Good recoveries (77-122%), precision in the 5% to 12% range and limits of detection, ranging from the low nanogramme per gramme level for 4tOP, 4nOP and E2 to the low microgramme per gramme level for nonylphenols, were obtained. The optimised method was applied for the determination of alkylphenol in the bile of thick-lip grey mullets fish bile from the Urdaibai estuary (UNESCO reserve of the Biosphere, Bay of Biscay), and high concentrations (2.3-14.2 µg/g), such as those obtained in polluted areas, were measured. E2 was determined in the bile of thick-lip grey mullets, intraperitoneally injected with E2.


Assuntos
Bile/enzimologia , Cromatografia Líquida de Alta Pressão/métodos , Estradiol/análogos & derivados , Fenóis/metabolismo , Ultrassom , Animais , Bile/química , Estradiol/análise , Estradiol/metabolismo , Peixes , Hidrólise , Espectrometria de Massas/métodos , Fenóis/análise
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