Biomedical subjects

J L Gómez-Ariza

Publications and source records attributed to J L Gómez-Ariza.

16 recordsLinked to original sources

PubMed2006

Multielemental fractionation in pine nuts (Pinus pinea) from different geographic origins by size-exclusion chromatography with UV and inductively coupled plasma mass spectrometry detection.

Pine nuts (Pinus pinea) from different geographical origin in Spain and Portugal have been investigated concerning total element content and metal-biomolecules size distribution patterns Mn, Zn, Ni and Cu. All the studied metals were at the highest concentration in pine nuts from Faro and at the lowest from Cataluña. The most abundant element in samples was Mn at concentrations in the range of 26 microg g(-1) (Cataluña) to 559 microg g(-1) (Faro). Zn was also present at high concentration in samples, from 25 microg g(-1) (Cataluña) to 113 microg g(-1) (Faro). To a deeper insight to obtain classification rules for samples, pine nuts were analyzed by size-exclusion chromatography (SEC) with UV detection and inductively coupled plasma mass spectrometry (ICP-MS). Two columns were used covering the molecular weigh range from < 10 to 70 kDa that allowed the discrimination of the studied samples. Data reveal that the most differential UV-profile with low molecular weight (LMW) column was obtained with pine nuts from Huelva. This column allows good discrimination in the range of 2126-1352 Da in which a lot of peaks can be used to differentiate samples. The UV profiles obtained with the high molecular weight (HMW) column allows a poorer differentiation of samples, but pine nuts from Huelva, Castilla and Madrid are clearly distinguished to the others. In relation to fractionation patterns of metals, Mn allows a good discrimination between samples (LMW column), Cu was the only one associated to fractions at MW > 70 kDa in sample from Cádiz, and profiles of Ni and Zn are clearly different in terms of abundance of peaks. All these chromatographic profiles for elements give valuable information about the geographical origin of the studied samples and the differences found are discussed in this work.

Chromatography, Gel↗

PubMed2006

Organotin contamination in the Atlantic Ocean off the Iberian Peninsula in relation to shipping.

Imposex in female snails, a bioindicator of TBT contamination, and the presence of organotins in snails' tissue and sediments were studied at nine sites off the western Iberian Peninsula. The study was part of a European project (acronym HIC-TBT) co-financed by the EU-LIFE programme, intending to investigate and communicate the impact of organotins from ships in marine ecosystems. Snails and sediments were sampled during two cruises in May/June 1999 and in January 2000 in areas of high, intermediate and low-shipping density. Imposex was found in female snails from several sampling sites, some of which had an imposex incidence of 100%. Differences in sensitivity were found between species; hence comparison of imposex levels between locations where different species were collected was not straightforward. Total organotin concentrations in sediments (sum of butyl and phenyltin compounds) ranged from 21 to 185 ng Sn g(-1) with higher values for most sites sampled in the vicinity of shipping lanes. Organotin concentration in snails' tissue ranged from <5 to 196 ng Sn g(-1), which are similar to those found in snails from other offshore areas contaminated by TBT. Overall, these results give further support to the recent ban on the use of organotin based antifouling paints to all ship size.

Animals↗

PubMed2006

Use of multiple headspace solid-phase microextraction and pervaporation for the determination of off-flavours in wine.

The occurrence of off-flavours in wines and especially the so-called "cork taint defect" represents one of the most serious problem in wine industry in which 2,4,6-trichloroanisole has been blamed as the main responsible. The development of analytical methods for haloanisoles determination in wine/cork represent a challenge, mainly due to food matrix complexity and low taste and odour (T&O) threshold levels which are generally beyond the sensitivity of the analytical systems. In this work, a method based on the combined use of the recently developed multiple headspace solid-phase microextraction (MHS-SPME) and gas chromatography-ion-trap mass spectrometry has been optimised for the determination of haloanisoles in wines. This powerful analytical methodology is compared with several analytical approaches based on pervaporation, an innovative membrane-based technique similar to dynamic headspace. Analytical features of the methods assayed reveal their suitability for the appraisal of haloanisoles in this matrix in which threshold odor concentrations are in the range 4-40 ng l(-1). The analytical approaches have been applied to the analysis of haloanisoles in different Spanish white and red wines, in which spiking experiments showed good recoveries for the methodologies assayed.

Anisoles↗

PubMed2006

Use of flow injection atmospheric pressure photoionization quadrupole time-of-flight mass spectrometry for fast olive oil fingerprinting.

The recently introduced technique of an atmospheric pressure photoionization (APPI) source coupled to quadrupole time-of-flight mass spectrometry (QqTOFMS) has been applied to fast olive oil fingerprinting on the basis of the accurate mass measurements obtained with this instrumentation. The key compounds can be characterized as [M+H]+ (produced by proton transfer) or as [M]+* (by charge transfer) ions in the mass spectra. [M+H]+ ions, however, show higher abundance, especially for triacylglycerols. Other ions present in APPI-MS are the acylium ion [RiCO]+ and [RiCO-H2O]+. This latter ion is absent in the electrospray ionization (ESI)-MS spectra, and this represents valuable complementary information. Several critical parameters in the APPI source were optimized such as LC eluent composition, ion spray voltage and, especially, declustering potential. APPI-QqTOFMS allows easy discrimination among different edible oils: olive, extra virgin olive, olive-pomace, hazelnut, sunflower, corn and several mixed oils, with high throughput (approximately 1 min per sample). Cluster analysis was applied to obtain the best experimental conditions for oil discrimination on the basis of declustering potential. Principal components analyses of these APPI-MS spectra show that the approach can be used for studies of olive oil adulteration with other oils, even in the case of hazelnut oil that exhibits a high chemical similarity with olive oil.

Corylus↗

PubMed2005

Guidelines for routine mercury speciation analysis in seafood by gas chromatography coupled to a home-modified AFS detector. Application to the Andalusian coast (south Spain).

A home-modified atomic fluorescence detector (mAFS) has been employed for mercury and methylmercury determination in bivalves from the Andalusian coast (south Spain). This modification consists on the inclusion of a quartz flow cell into the detector, which increases the concentration of mercury atoms in the detector and therefore enhances sensitivity about two fold. Two analytical approaches for mercury speciation based on the coupling of gas chromatography on-line pyrolysis and mAFS (GC-Pyro-mAFS) have been tested. The first approach (Method 1) is based on aqueous ethylation followed by extraction into an organic solvent, and the second one (Method 2) in the extraction of monoalkylated mercury as chloride. Method 1 is a rapid procedure but not sensitive enough for the analysis of methylmercury in non-polluted sites (detection limit: 20 ng g(-1) as mercury, wet basis). The second one is quite more sensitive (detection limit: 0.2 ng g(-1), wet weight), but sample treatment is cumbersome and time-consuming. The optimum range for mercury determination for both methods are complementary and exhibit an overlapping measurable concentration range (OMCR) in which methylmercury can be indistinctly determined (75-100 ng g(-1) as mercury, wet basis). The suitability of both methods has been assayed with spiking experiences at levels within the OMCR with good recoveries. Both approaches have been validated with two certified reference materials (BCR-463, mercury and methylmercury in tuna fish; and NIST-2977, organic contaminants and trace metals in mussel tissue). Both procedures have been used for the analysis of three species of bivalve molluscs collected along the Andalusian coast (south Spain), all of them employed for human consumption (Chamelea gallina, Donax trunculus and Scrobicularia plana), and their potential use in routine analysis has been established.

Animals↗

PubMed2004

Dynamic headspace coupled to perevaporation for the analysis of anisoles in wine by gas chromatography-ion-trap tandem mass spectrometry.

Off-flavours in wines are mainly due to the presence of 2,4,6-trichloroanisole and other haloanisoles. The purpose of this study was to develop a method based on the coupling of dynamic headspace and perevaporation to GC-MS-MS to attain better analyte sensitivity and selectivity. The approach has been applied to the analysis of 2,6-dichloroanisole, 2,4,6-trichloroanisole and 2,4,6-tribromoanisole in various wines. For these compounds that cause taste and odour problems, the method was linear from the quantification limit to 3 ng for all the analytes with recoveries greater than 80% and satisfactory precision. Detection limits were as low as 2-36 ng l(-1).

Anisoles↗

PubMed2004

Analysis of anisoles in wines using pervaporation coupled to gas chromatography-mass spectrometry.

Two procedures for the determination of 2,4,6-trichloroanisole, 2,6-dichloroanisole and 2,4,6-tribromoanisole in tainted wines have been developed. Both methods are based on pervaporation (PV) of the analytes and final determination by gas chromatography-ion-trap tandem mass spectrometry (GC-MS). In the Approach A, pervaporation was directly coupled to the GC-MS system (PV-GC-MS/MS) and in Approach B a solid-phase cryogenic trap-thermal desorption (CT-TD) device was connected to the pervaporator (PV-CT-TD-GC-MS/MS). Results show that last coupling present better sensitivity as well as precision. Detection limits (DLs) for 2,4,6-trichloroanisole were estimated to be 25.8 and 4.2 ng l(-1) for Approaches A and B, respectively, when 10 ml of sample was analysed. Linear range of the calibration curves ranged from quantification limit to 15 ng for PV-GC-MS/MS and from quantification limit to 2 ng for PV-CT-TD-GC-MS/MS. Due to the low threshold odour concentration of these compounds in wine, Approach B is proposed as a reliable method for analytical quality control of this product.

Anisoles↗

PubMed2004

Determination of flavour and off-flavour compounds in orange juice by on-line coupling of a pervaporation unit to gas chromatography-mass spectrometry.

A method for the analysis of several volatiles compounds responsible for orange juice flavour (ethyl butanoate, limonene, linalool, alpha-pinene, geranial, neral and alpha-terpineol) has been developed. The isolation of this compounds was carried out by pervaporation (PV) followed by on-line gas chromatography-mass spectrometry (GC-MS). The coupling PV-GC-MS has been successfully applied to fresh hand-squeezed orange juices and frozen concentrated ones in order to establish differences in their flavour profile. Method has been validated with recovery spike experiments which showed its applicability for a wide range of concentrations.

Beverages↗

PubMed2004

Evolution of biological effects of Aznalcóllar mining spill in the Algerian mouse (Mus spretus) using biochemical biomarkers.

The status of Guadiamar stream, polluted in 1998 by metals spilled from a pyrite tailings dam, was monitored from 1999 to 2001 to assess possible biological effects in terrestrial ecosystems of Doñana National Park (DNP) (Andalusia, SW Spain). The Algerian mouse (Mus spretus) was used as bioindicator at different Guadiamar and Doñana sites. Eleven biochemical parameters, including the activities of antioxidative and biotransforming enzymes and oxidative damages to biomolecules, were assayed in liver as biomarkers responsive to metals and organic pollutants. In 2001, metals were also determined in kidney and their possible correlation with biomarker responses was studied. Contents of Pb, Cd and As significantly correlated with several antioxidative enzymes. Biomarkers responsive to oxidative stress indicate the presence of transition metals in the high and medium Guadiamar course, and their response diminished with the distance to the collapsed dam. The high ethoxyresorufin-O-deethylase (EROD) activity of mice from the medium and low Guadiamar course point to organic pollutants, such as the pesticides used in intensive crops grown in areas nearby Doñana. The increasing responses of several biomarkers at reference sites may suggest a progressive pollution of key Doñana ecosystems.

Animals↗

PubMed2002

Determination of polychlorinated biphenyls in biota samples using simultaneous pressurized liquid extraction and purification.

In order to reduce time and cost of analysis, a new pressurised liquid extraction method that automatically and rapidly achieves quantitative and selective (i.e., lipid-free) extraction of polychlorinated biphenyls (PCBs) in biota tissues was optimized. It consists of on-line clean-up by inclusion of sorbents in the extraction cell. The freeze-dried sample is dispersed with Florisil and loaded in the extraction cell containing an extra amount of Florisil. The extraction is performed under mild conditions using 55 ml of a dichloromethane-pentane (15:85) mixture, a temperature of 40 degrees C, a static extraction time of 10 min and two extraction cycles. The Florisil retains coextracted lipids from the matrix, and the extract, after pre-concentration, is clean enough for direct injection into GC-MS and GC-electron-capture detection (ECD). Quantitative recoveries (from 90 to 106%) are obtained for both native and spiked PCB congeners in samples with a high lipidic content (up to 42% dry mass, in spoonbill eggs). The reproducibility of replicate extractions was better than 11% relative standard deviation. Method detection limits were in the ranges of 0.001-0.004 and 0.002-0.07 ng g(-1) dry mass for GC-ECD and GC-MS-MS, respectively. The method was validated using the standard reference material SRM 2974 (a mussel tissue) from the US National Institute of Standards and Technology, compared to Soxhlet and matrix solid-phase dispersion extraction methods, and used to evaluate the contamination by PCBs in bivalves from South of Spain.

Animals↗

PubMed2002

Determination of an arsenosugar in oyster extracts by liquid chromatography-electrospray mass spectrometry and liquid chromatography-ultraviolet photo-oxidation-hydride generation atomic fluorescence spectrometry.

HPLC-UV-HG-AFS analysis of aqueous extracts of oysters (Crassostrea gigas) taken from the southwestern Atlantic coast of Spain showed the presence of arsenite, arsenate, dimethylarsinic acid and an unidentified arsenic peak. Subsequent analysis of the oyster samples by LC-electrospray MS and comparison with four standard dimethylarsinoylribosides (arsenosugars), showed that the previously unidentified peak was an arsenosugar (arsenosugar 2). When the arsenosugar in the oyster was quantified using the two detection methods and external calibration with standard arsenosugar, there was a large discrepancy between the two sets of results. The LC-MS analysis was strongly affected by the sample matrix and gave concentrations 50% lower than those obtained by AFS detection. When the method of standard addition was applied to the LC-MS analysis, the results were comparable to the AFS data. The matrix effects were eliminated by subjecting the extract to a clean-up procedure with anion-exchange and gel permeation preparative chromatography before the LC-MS analysis. The arsenosugars gave a small signal without photo-oxidation when they were analysed by HPLC-HG-AFS. Possibly this resulted from partial decomposition of the arsenosugar to dimethylarsinic acid under the acidic conditions employed in the hydride generation step.

Animals↗

PubMed2000

Column-switching system for selenium speciation by coupling reversed-phase and ion-exchange high-performance liquid chromatography with microwave-assisted digestion-hydride generation-atomic fluorescence spectrometry.

Speciation of selenocysteine (SeCys), selenomethionine (SeMet), selenoethionine (SeET), selenite (Se(IV)) and selenate (Se(VI)) has been accomplished using high-performance liquid chromatography, with the aid of an anion exchange column and a reversed-phase column, both connected through a six-port switching valve. On-line microwave-assisted digestion and hydride generation steps were performed prior to the atomic fluorescence detection. The elution of the seleno amino acids was accomplished in the reversed-phased column using water as mobile phase. Selenite and selenate were separated in the anion exchange column, using gradient elution with an acetate buffer. The separation of the five selenium compounds took place in 15 min. The detection limits obtained ranged between 0.6 and 0.9 microg l(-1). Values of r>0.998 were obtained for linear fit graphs. A commercial available urine sample was analyzed, in which SeCys and Se(IV) were quantified.

Chromatography, High Pressure Liquid↗

PubMed2000

Temporal fluctuations of tributyltin in the bivalve Venerupis decussata at five stations in southwest Spain.

Filter feeding clams, Venerupis decussata, were sampled every 4 months for 8 years at five locations on the southwest Spain coast and analysed for organotins. All the stations showed a significant sinusoidally shaped seasonal evolution pattern for tributyltin (TBT) superimposed upon a linear decreasing tendency. The amplitude and frequency of fluctuations differed among stations and were correlated to the harbour activities. Fluctuations were greatest at stations with the greatest TBT presence. The long-term trend of TBT in clams indicated half-life values of about 7-14 years. During 1993, water and sediment samples were also collected at monthly intervals and analysed. Correlations between TBT bivalve contents and water concentrations were higher than those found between biota and sediments.

Journal Article↗

PubMed1999

Evaluation of the state-of-the-art of butyl- and phenyltin compound determinations in freshwater sediment prior to certification of a reference material.

In order to control the quality of butyl- and phenyltin compound determinations in sediment, the Standards, Measurements and Testing Programme (formerly BCR) of the European Commission has started a project, the final aim of which is to certify a freshwater sediment for its contents of a range of organotin compounds (mono-, di- and tributyltin, and mono-, di- and triphenyltin). The first part of this project involved an interlaboratory study which aimed to test the feasibility of preparation of candidate freshwater sediment reference material and to detect and remove most of the pitfalls observed in organotin determinations. This paper presents the main results of this interlaboratory study carried out prior to the certification campaign. The agreement obtained among laboratories for the six compounds determined was considered to reflect the state-of-the-art and was encouraging enough to decide upon the organisation of a certification campaign, which will be concluded in June 1999.

Environmental Monitoring↗

PubMed1999

Stability and storage problems in organotin speciation in environmental samples.

The stability of both tributyltin (TBT) and triphenyltin (TPT) in water, sediment, oysters and cockles was studied over a period of 18 months using several storage conditions. Butyltins were stable in unacidified sea-water stored in polycarbonate bottles in the dark at 4 degrees C for 7 months, but half of the TBT concentration was lost after 540 d. A comparable preservation time was achieved for butyltins stored on C18 cartridges at room temperature. However, phenyltins extracted from sea-water were stable for only 60 d stored on cartridges and even more pronounced losses (about 90% after 540 d) occurred when they were stored in either polycarbonate or Pyrex glass bottles. Losses of organotins were observed in sediments after air drying and pasteurization treatments using a freeze-dried sediment as a comparator, whereas both butyltin and phenyltin species remained stable in sediments stored at -20 degrees C for the 18 months tested, irrespective of the treatment used for stabilization. Air drying followed by pasteurization was shown to be superior to other treatments for the stabilization of organotin compounds in sediments stored at higher temperatures, but 30% of TBT was lost after 540 d at 25 degrees C. Finally, butyltins were stable in both frozen cockles and oysters in the dark over a 7 month period and in freeze-dried samples stored at 4 degrees C for 5 months, but TBT losses of about 70% were observed after 540 d.

Animals↗

PubMed1999

Determination of dialkyldiselenides in water by gas chromatography-mass spectrometry using 1-fluoro-2,4-dinitrobenzene as derivatization reagent.

The feasibility of gas chromatography-mass spectrometry for the speciation of traces of dialkyldiselenides in the presence of dialkylselenides and inorganic selenium species is described, and the procedure is applied to environmental samples. The analysis is based on the reaction of dialkyldiselenide species with 1-fluoro-2,4-dinitrobenzene after volatilization of selenium species as alkylselenols using a volatilization and trap device. Parameters affecting the volatilization and derivatization of the selenium compounds are discussed, and the performance of the method is described. The approach reaches detection limits in the order of nanograms (after a preconcentration step) and has been applied to the analysis of dimethyldiselenium and diethyldiselenium in natural waters.

Dinitrofluorobenzene↗