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63
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Introduction
Current institution
Current position
- Associate Professor in the department of Analytical Chemistry at UGR and Head of Research Group "AnaMa"
Additional affiliations
January 2012 - present
January 2001 - present
Publications
Publications (63)
Currently, the combination of fingerprinting methodology and environmentally friendly and economical analytical instrumentation is becoming increasingly relevant in the food sector. In this study, a highly versatile portable analyser based on Spatially Offset Raman Spectroscopy (SORS) obtained fingerprints of edible vegetable oils (sunflower and ol...
Nowadays, the combination of fingerprinting methodology with friendly environmental and economical analytical instrumentation are becoming increasingly relevant in the food sector. In this study, a highly versatile portable analyser based on Spatially Offset Raman Spectroscopy (SORS) to obtain the edible vegetable oils (sunflower and olive oils) fi...
BACKGROUND
Tigernut is a typical foodstuff from a specific region of Valencia (Spain) called ‘L'Horta Nord’, where it is commercialized under a Protected Designation of Origin (PDO) as Chufa de Valencia (‘Valencia's tigernut’). PDO‐recognized tigernuts present unique characteristics associated with their particular production region. Increasing dem...
Oak wood is the main material used by coopers to manufacture casks for the aging of spirits or wines. Phenolic compounds are the main components extracted from the wood during spirit aging. In the present study, a chemometric approach based on unsupervised (PCA) and supervised (PLS-DA) pattern recognition techniques has been applied to the chromato...
Brandy de Jerez is a unique spirit produced in Southern Spain under Protected Geographical Indication “Brandy de Jerez” (PGI). Two key factors for the production of quality brandies are the original wine spirit and its aging process. They are significantly conditioned by specific variables related to the base wine and the distillation method employ...
Brandies are spirits produced from wine spirit and wine distillates. The original wines selected to be distilled to produce the wine spirits as well as the distillation method used determine, to a large extent, the organoleptic characteristics of the final products. The young wine spirits evolve during their aging in oak casks, this being another k...
The European hazelnut (Corylus avellana L.) is a tree nut that is mainly produced in Turkey, Italy and USA and used by the confectionery industry to obtain sweets and chocolate spreads. Among all the known cultivars/origins, the "Tonda Gentile Trilobata" from Piedmont (Italy) is highly appreciated due to its organoleptic properties and considered,...
European hazelnuts (Corylus avellana L.) are a key ingredient for the confectionery industry with a distinctive flavor profile and high nutritional quality. However, the high-fat content makes raw kernels prone to autoxidation that takes place during storage. Fatty acids hydroperoxides (i.e., primary products of oxidation) readily decompose by form...
Extra virgin olive oil is a potentially vulnerable foodstuff that can be mixed with other vegetal edible oils including poorer quality olive oils in order to obtain illicit profits. These unauthorized operations may take place at any stage of the production process and radically affect the chemical composition. In this paper, the analysis of differ...
There is a large amount of literature relating to multivariate analytical methods using liquid chromatography together with multivariate chemometric/data mining methods in the food science field. Nevertheless, dating the obtained results cannot be compared as they are based on data acquired by a particular analytical instrument, thus they are instr...
One of the main causes for the sparse use of multivariate analytical methods in routine laboratory work is the dependency on the measuring instrument from which the analytical signal is acquired. This issue is especially critical in chromatographic equipment and results in limitations of their applicability. The solution to this problem is to obtai...
This chapter includes and describes different applications of chromatographic techniques for food authentication using the (bio)markers, profiling and fingerprinting approaches, and the different chemometric tools used are also discussed. Finally, the different applications of chromatographic techniques for food authentication are summarised in sev...
Fat-spread products, including margarines, are an emulsion of water derived from vegetable and/or animal fats, which is obtained through a hydrogenation process. In the market there are different types of fat-spreads and their composition depends on the country where they are produced. It is therefore desirable to identify the geographic origin of...
Sensory properties are critical characteristics that determine quality and can be evaluated by trained tasting panels. The panels function as multi-sensor measuring instrument and need the use of reference materials (RMs) for training.
The homogeneity between units packaged from a batch of RM can be evaluated by gas chromatography coupled to flame...
Fat-spread products are a stabilized emulsion of water and vegetable oils. The whole fat content can vary from 10 to 90% (w/w). There are different kinds, which are differently named, and their composition depends on the country in which they are produced or marketed. Thus, having analytical solutions to determine geographical origin is required. I...
The risk assessment of pollution associated with metal extraction process is a social responsibility. The initial goal of this type of assessment should be the use of a methodology able to combine the use of easy application, low cost and high efficiency-techniques to provide the necessary information with the least amount of investment in time and...
In recent years, the variety and volume of data acquired by modern analytical instruments in order to conduct a better authentication of food has dramatically increased. Several pattern recognition tools have been developed to deal with the large volume and complexity of available trial data. The most widely used methods are principal component ana...
In Morocco, the recovery of olive agro-industrial by-products as potential sources of high-added value substances has been underestimated so far. A comprehensive quantitative characterization of olive leaves’ bioactive compounds is crucial for any attempt to change this situation and to implement the valorization concept in emerging countries. Thus...
This paper describes and discusses the application of trimethylsilyl (TMS)-4,4'-desmethylsterols derivatives chromatographic fingerprints (obtained from an off-line HPLC-GC-FID system) for the quantification of extra virgin olive oil in commercial vinaigrettes, dressing salad and in-house reference materials (i-HRM) using two different Partial Leas...
The formal recognition of quality in the laboratory context dates from the end of the twentieth century, when the first written standards, outlining specific quality requirements, were published. Since then, and for almost 30 years, the concept of quality related to the activity of analytical laboratories has evolved significantly. It has also curr...
A method to discriminate virgin olive oil from other edible vegetable oils such as, sunflower, pomace olive, rapeseed, canola, corn and soybean, applying chemometric techniques to the liquid chromatographic representative fingerprint of sterols fraction, is proposed. After a pre-treatment of the LC chromatogram data - including baseline correction,...
In order to improve the separation of the sterol classes present in vegetable oils, an isocratic off-line HPLC fractionation of unsaponifiable has been developed using a cyano-bonded phase column as stationary phase and hexane/tert-butylmethyl ether (80:20 (v/v)) as mobile phase, which permits to obtain them in less than 12 min. With the aim of eva...
This paper discusses the estimation of the uncertainty of the chromatographic determination of 4-desmethyl sterols in vegetable oils, combining the off line HPLC fractionation of the analytes, from the unsaponifiable fraction of the samples, with their determination as TMS derivatives by GC(FID), using the data obtained from a single internal calib...
The combination of "ex situ" portable X ray fluorescence with unsupervised and supervised pattern recognition techniques such as hierarchical cluster analysis, principal components analysis, factor analysis and linear discriminant analysis have been applied to rock samples, in order to validate a "in situ" macroscopic rock samples classification of...
In this work, the potential soil contamination in the abandoned mining area of Rodalquilar (SE, Spain) is studied using portable X-ray fluorescence (PXRF). Measurements were made in situ, and data were statistically treated to study the spatial distribution of the anomalous values of trace elements. The elements exceeding the background values of t...
Purpose
We used the different soluble-in-water concentrations of As, Cu, Mn, Pb and Zn from contaminated soils in an abandoned mining area (anthropogenic origin) to assess the phytotoxicity of the abandoned site using the results obtained with a Lactuca sativa L. bioassay.
Material and methods
The study has been carried out on potentially polluted...
The Rodalquilar gold mining district (Almería, south Spain) is an abandoned mining area extensively exploited since roman age up to the end of last century. Different types of metallic mineralizations appear in the zone, related with volcanic rocks, usually in the form of sulphides or native elements. As consequence of the extraction of metals (Au,...
Plant sterols, also called phytosterols, are minor bioactive compounds very important for human nutrition because they have the same basic function in plants as cholesterol in animals; that is, they play a key role in cell membrane function and are non-nutritive compounds whose chemical structure differs from that of cholesterol only by minor modif...
Unsupervised and supervised pattern recognition techniques such as hierarchical cluster analysis, principal component analysis, factor analysis and linear discriminant analysis have been applied to water samples recollected in Rodalquilar mining district (Southern Spain) in order to identify different sources of environmental pollution caused by th...
Purpose We used the different soluble-in-water concentrations of As, Cu, Mn, Pb and Zn from contaminated soils in an abandoned mining area (anthropogenic origin) to assess the phytotoxicity of the abandoned site using the results obtained with a Lactuca sativa L. bioassay. Material and methods The study has been carried out on potentially polluted...
Calibration is an operation whose main objective is to know the metrological status of a measurement system. Nevertheless, in analytical sciences, calibration has special connotations since it is the basis to do the quantification of the amount of one or more components (analytes) in a sample, or to obtain the value of one or more analytical parame...
If a matrix effect is detected during the validation stage of an analytical method, the standard addition methodology must be applied. To reach a good estimation of the uncertainty associated with the determination, an adequate identification and evaluation of each uncertainty source should be done. As an example to illustrate how to calculate the...
This article establishes the estimation of the uncertainty associated with the chromatographic determination of biogenic amines. The authors identify and estimate each source of uncertainty to establish the accuracy of results and to obtain a better understanding of the method. Thus, measurement uncertainty was split into two sections: uncertainty...
Biogenic amines, as dabsyl derivatives, were determined in beer samples, intermediate products, and raw materials (malt and maize) by HPLC. A procedure for the extraction of the amines from malt and maize with diluted hydrochloric acid was optimised by combining a Response Surface Methodology with a Simultaneous Decision Making Approach. The result...
Pattern recognition techniques, such as principal component analysis, cluster analysis, and linear discriminant analysis, have been applied to samples of red, white, and rosé wines to determine whether some biogenic amines could be considered as chemical descriptors. Eight amines (tryptamine, phenylethylamine, putrescine, cadaverine, histamine, tyr...
The application of the supported liquid membrane (SLM) technique for the extraction of biogenic amines is presented. For the extraction of these compounds, the SLM system has been applied, using di-2-ethylhexyl phosphoric acid as an anionic carrier incorporated into the membrane phase. The optimization of the extraction process, involving the compo...
The authors describe a new approach to verifying robustness testing in high performance liquid chromatography. They use the linear interpretation of the response obtained from an experimental domain close to the procedural conditions. The authors applied the procedure, based upon multiple linear regression analysis of a data set obtained from a wel...
Mixtures of clays are often used in the manufacture of bricks, with distinct additives for diverse ends. The firing process, however, determines the final properties of the material. In this work, ultrasound and mechanical tests have been combined with a statistical tool, the analysis of variance (ANOVA), to analyse the mineralogical and physical c...
A robustness test for the separation and LC determination of eight biogenic amines (histamine, tyramine, phenylethylamine,
tryptamine, cadaverine, putrescine, spermidine and spermine) has been made in order to validate the method, which involves
derivatization of the amines with dabsyl chloride, and analysis by reversed-phase liquid chromatography...
A method for the simultaneous solvent extraction into IBMK from acidic medium of Cd(II), Cu(II), Co(II), Cr(VI), Ni(II), Pb(II) and Zn(II) as dibenzyldithiocarbamates and determination by AAS is proposed. Formal techniques for multidimensional optimization have been used, in particular, the response surface methodology, in order to obtain the best...
In the last few years special attention has been paid to the pre-column derivatization of biogenic amines with dabsyl chloride
because proper experimental conditions for this reaction are very important. In this study, an experimental design (Doehlert
design) was used to optimize the variables involved in the dabsylation of the following amines: hi...
A method suitable for the determination of eight biogenic amines (histamine, tyramine, phenylethylamine, tryptamine, cadaverine, putrescine, spermidine and spermine) in wines has been developed. The method involves derivatization of the amines by treatment with dabsyl chloride, after which the derivates were analysed by reversed-phase liquid chroma...
Lime mortar has been used throughout history despite current substitution by hydraulic mortars (cements). The chemical composition of the lime used in its manufacture, however, is determined by local geology. In addition, the type of slaking, which depends on the amount of water used, gives rise to different types of lime. The result is that the be...
The elements La, Y, Pr, Nd, Sm and Ce form with MgII and purpurin (1,2,4-trihydroxyanthraquinone) mixed-metal complexes which can be extracted into isobutyl methyl ketone at pH 7.5. The total content of these metals can be determined by measuring the magnesium absorbance by AAS. The proposed method, which permits the determination of concentrations...
An experimental design (Doehlert matrix design) has been carried out in this study to optimize the experimental variables for the simultaneous solvent extraction of Fe, V, Mo and Sn in isobutyl methyl ketone–tributyl phosphate with 5,5′-methylenedisalicylohydroxamic acid. Four variables were examined: pH and perchlorate, chelating reagent and syner...
A reversed-phase liquid chromatographic method for the determination of titanium with 5,5′-methylenedisalicylohydroxamic acid
(MEDSHA) is described. The titanium(IV) complex is formed in a MeOH–5 × 10−3M H2SO4 medium and injected onto a Polyspher RP18 column for chromatography. The mobile phase is H2SO4 (5 × 10−3M):MeOH (4:96, v/v) and contains 1.5...
A statistical procedure to validate a chromatographic method is described. It starts by establishing the linear dynamic range (LDR) in both peak-height and peak-area, in order to choose the best instrumental signal for the quantitative analysis. Secondly, the performance characteristics of the method (sensitivity, precision and detection limit) are...
A normal-phase high-performance liquid chromatographic method for the selective simultaneous determination of vanadium and molybdenum with N-benzoyl-N-phenylhydroxylamine (BPHA) is described. The V(V)-BPHA and Mo(Vl)-BPHA complexes were preconcentrated by solvent extraction into chloroform and injected on to a nitrile-bonded column for chromatograp...
A normal-phase liquid Chromatographie method for the selective determination of molybdenum with N-benzoyl-N-phenylhydroxylamine is described. The molybdenum(VI) complex was preconcentrated by extraction into chloroform and injected onto a nitrile column for chromatography. The mobile phase was a 0.075 M solution of reagent in chloroform (stabilized...
A method was developed for the determination of tin based on the extraction of its 5,5'-methylenedisalicylohydroxamic acid complex with 1.09M isobutyl methyl ketone in tributyl phosphate. After the samples were treated with nitric and hydrochloric acid, the aqueous phase was made to 0.05M in perchloric acid. When the ratio of aqueous phase to organ...
A normal-phase high-performance liquid chromatography (HPLC) method for the selective determination of vanadium with N-phenylbenzohydroxamic acid (PBHA) is described. The Vv-PBHA complex was preconcentrated by solvent extraction into trichloromethane and injected on to a silica gel column for HPLC, with a mobile phase of methanol-trichloromethane (...
A method is described for the flame atomic absorption spectrometry (AAS) determination of vanadium, down to microgram level, in food samples and petroleum crudes. The procedure is based on the synergistic extraction of the V(V)-5,5′-methylene-disalicylohydroxamic acid (MEDSHA) complex with a 0.5 M tributyl phosphate (TBP) solution in isobutyl methy...
