Regional Institute for Applied Chemistry Research

Ciudad Real, Spain

Regional Institute for Applied Chemistry Research

Ciudad Real, Spain

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Lerma-Garcia M.J.,University of Castilla - La Mancha | Lerma-Garcia M.J.,Regional Institute for Applied Chemistry Research | Simo-Alfonso E.F.,University of Valencia | Zougagh M.,Regional Institute for Applied Chemistry Research | And 2 more authors.
Talanta | Year: 2013

Two new gold nanoparticle (NP) coated materials (silica supported on gold NP with and without ionic liquid) were synthesized for solid phase extraction of sulfonylurea herbicides (SUHs), such as bensulfuronmethyl (BSM), metsulfuron-methyl (MSM), pyrazosulfuron-methyl (PSM), thifensulfuron-methyl (TFM) and triasulfuron (TS), from water samples, followed by capillary liquid chromatography coupled to diode array detection (CLC-DAD). Several factors influencing the preconcentration efficiency of SUHs and its subsequent determination, such as pH of the sample, eluent and reusability of sorbents, have been investigated. Under the optimum conditions, the developed method allowed the determination of BSM, MSM, PSM, TFM and TS in a linear range between 0.05 and 1.00 μg mL-1, with relative standard deviation values lower than 4.5% (n=10), in all cases. Detection limits within 0.002-0.009 μg mL-1 range were achieved. The usefulness of the proposed method was demonstrated by the analysis of river water samples, in which recoveries between 83.9 and 105.0% were obtained. The Au-NP-ionic liquid-functionalized silica sorbent showed higher recoveries (selectivity) for the SUHs than the commercially available C18 sorbents. © 2012 Elsevier B.V. All rights reserved.


Bouri M.,University of Castilla - La Mancha | Bouri M.,ensa Inc | Salghi R.,ensa Inc | Zougagh M.,Regional Institute for Applied Chemistry Research | And 2 more authors.
Analytical Chemistry | Year: 2013

In this technical note, an interface for coupling commercially available capillary electrophoresis (CE) equipment to an evaporative light scattering detector (ELSD) is described. The nebulization process was identified as the most critical parameter for performing the reliable coupling between both pieces of equipment. Therefore, appropriate modifications in the nebulization chamber and in the conventional nebulizer were brought to make ELSD fully compatible with CE. The impact of the customized interface on CE separation and detection was evaluated in terms of resolution and sensitivity. ELSD can be considered as an attractive alternative to other CE detection systems (e.g., UV-vis, fluorescence, electrochemical detection, or even MS detection), particularly those in which derivatization is needed. This advantage is due to the versatility and the quasi-universality of ELSD. Thus, sensitive and fast separations of several compounds were performed using this CE-ELSD customized arrangement, which opens up an interesting analytical potential for the determination of compounds not presenting sensitive UV-vis chormophore, fluorophore, or electroactive groups. Carbohydrates were selected in this work to demonstrate the applicability of CE-ELSD coupling. © 2013 American Chemical Society.


Bouri M.,University of Castilla - La Mancha | Bouri M.,ensa Inc | Lerma-Garcia M.J.,University of Castilla - La Mancha | Lerma-Garcia M.J.,Regional Institute for Applied Chemistry Research | And 4 more authors.
Talanta | Year: 2012

A rapid and selective method for the extraction and determination of catecholamines (CLs) from urine samples has been successfully developed using a magnetic molecularly imprinted polymer (MMIP) as a sorbent material. The MMIP has been prepared using dopamine hydrochloride (DA) as template molecule, methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EDMA) as cross-linking agent and Fe3O4 magnetite as magnetic component. The extraction was carried out by stirring urine samples with the magnetic polymer. When the extraction was completed, the MMIP, together with the captured analytes, was easily separated from the sample matrix by an adscititious magnet. The analytes desorbed from the MMIP were determined by capillary electrophoresis (CE). It was shown that the MMIP had high affinity and selectivity toward DA and other structurally related CLs such as 3-methoxytyramine hydrochloride (MT), DL-normetanephrine hydrochloride (NME), DL-norephinephrine hydrochloride (NE) and (±) epinephrine (E). Different parameters affecting the extraction efficiency were evaluated in order to achieve the optimal pre-concentration of the analytes and to reduce non-specific interactions. Under the optimal conditions, the CL limits of detection were at the 0.04-0.06 μM range. The relative standard deviations of migration time and response ranged from 0.7% to 1.4% and from 2.9% to 5.5%, respectively. The proposed method was successfully applied to determine CLs, including MT, NME, DA, NE and E in human urine samples. © 2012 Elsevier B.V.


De Andres F.,University of Castilla - La Mancha | Zougagh M.,University of Castilla - La Mancha | Castaneda G.,University of Castilla - La Mancha | Rios A.,University of Castilla - La Mancha | Rios A.,Regional Institute for Applied Chemistry Research
Analytical and Bioanalytical Chemistry | Year: 2010

A rapid and simple method for separation and detection of six heterocyclic aromatic amines (2-amino-1-methyl-6-phenylimidazo [4,5-b]-pyridine, 2-amino-1-methyl-imidazo [4,5-f]-quinoline, 2-amino-3,8-dimethyl-imidazo [4,5-f]-quinoxaline, 2-amino-3,7,8-trimethyl-imidazo [4,5-f]-quinoxaline, 2-amino-3,4,8-trimethyl-imidazo [4,5-f]-quinoxaline, and 2-amino-3,4-dimethyl- imidazo [4,5-f]-quinoline) in human urine samples is proposed to reflect daily intake and recent HAAs exposure. This method comprises previous clean-up and preconcentration of the analytes on Strata-X reversed phase extraction cartridges followed by capillary liquid chromatography (CLC) and evaporative light-scattering detection (ELSD). A mobile phase of acetonitrile and ammonium acetate 35 mM at pH 5.15 through a gradient of composition and a flow rate of 15 μL min-1 resulted in good separations of the analytes. Temperature and gas pressure were optimized for detection. The CLC-ELSD allows the separation and quantification of HAAs with good resolution, precision, and sensitivity. The usefulness of the proposed method was demonstrated by the analysis of synthetic and natural human urine samples spiked with different concentration levels of heterocyclic amines. © 2010 Springer-Verlag.


Rios A.,University of Castilla - La Mancha | Zougagh M.,Regional Institute for Applied Chemistry Research | Zougagh M.,University of Castilla - La Mancha
TrAC - Trends in Analytical Chemistry | Year: 2016

The recent advances involving the use of magnetic nanomaterials for improving different steps of analytical processes were revised. Magnetic nanomaterials are unique tools for the simplification of the sample preparation working under a solid phase (micro)extraction format, in order to provide the appropriated selectivity (clean-up) and sensitivity (preconcentration) of many new analytical methods, or improving this step in already existing ones. In addition, magnetic nanomaterials can play a key role for the separation processes (chromatographic or electrophoretic), in which some analytical methods are based. The third interesting incidence of magnetic nanomaterials are in the detection step, showing new advantageous possibilities. All these aspects are revised in this article. © 2016 Elsevier B.V.


Rios A.,University of Castilla - La Mancha | Rios A.,Regional Institute for Applied Chemistry Research | Zougagh M.,Regional Institute for Applied Chemistry Research
TrAC - Trends in Analytical Chemistry | Year: 2013

The integration of sample treatment into a micro total analytical system (μ-TAS) represents one of the remaining hurdles towards achieving truly miniaturized systems. The challenge is made more complex by the enormous variation in samples to be analyzed. Moreover, the pretreatment technique has to be compatible with the analytical device to which it is coupled, in terms of time, reagent and power consumption, and sample volume.This review, with more than 140 references, presents some recent advances and novel strategies for sample preparation in μ-TASs. We classify μ-TAS sample-preparation methods according to the mechanism that links the analyte(s) of interest to substrates: filtration, cell lysis, liquid-liquid extraction, solid-phase extraction, droplet membrane droplet, treatment by nanomaterials, stacking and isotachophoresis. We compare these techniques in terms of sample flexibility, arguing for these applications in some fields, such as biological and environmental. These discussions can help to determine the appropriate sample-preparation technique for generating a true μ-TAS. We provide a critical discussion and some key conclusions. © 2012 Elsevier Ltd.


Rios A.,University of Castilla - La Mancha | Rios A.,Regional Institute for Applied Chemistry Research | Zougagh M.,Regional Institute for Applied Chemistry Research | Bouri M.,University of Castilla - La Mancha | Bouri M.,Regional Institute for Applied Chemistry Research
Analytical Methods | Year: 2013

This review, with more than 170 references, presents a general overview of the use of magnetic nanoparticles (MNPs) to perform sample preparation. In this way, the main types of MNPs used for this purpose, such as magnetic molecularly imprinted polymer (MMIP), noble metal coated MNPs, carbon nanotubes (CNTs), quantum dots (QDs), silica, and surfactant are described in terms of their composition, properties, and synergetic potential. Finally, some examples of their analytical applications are reported, as well as pointing out possible future applications of MNPs in the analytical field. © 2013 The Royal Society of Chemistry.


Bouri M.,University of Castilla - La Mancha | Salghi R.,Ecole nationale de science appliquees | Zougagh M.,Regional Institute for Applied Chemistry Research | Rios A.,University of Castilla - La Mancha | Rios A.,Regional Institute for Applied Chemistry Research
Electrophoresis | Year: 2013

An improved and efficient method for the determination of underivatized amino acids based on the use of CE coupled to evaporative light scattering detector (ELSD), involving carbon nanotubes, was successfully developed. Carboxyled single-walled carbon nanotubes were used for the first time to perform the clean-up of the analyzed samples, which were afterwards analyzed by CE-ELSD. White tea samples were used to demonstrate the usefulness of the CE-ELSD coupled methodology. A suitable interface, based on a triple tube design sprayer, was developed and successfully used for coupling both instruments. Parameters affecting the separation and determination, including the elimination of interferences, were studied and properly optimized. Under the optimized conditions good resolution was achieved for the separation of seven amino acids. The precision of the method, expressed as RSD, was found within the 3.5-5.3% range. The LOD obtained for the proposed method were in the 1.2-2.1 pg range and the LOQ, were in the 2.0-11.5 pg range, with injection pressure of 5 KPa for 20 s (15.3 nL). This method is simple, rapid, and selective compared with other conventional techniques. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Rios A.,University of Castilla - La Mancha | Rios A.,Regional Institute for Applied Chemistry Research | Zougagh M.,Regional Institute for Applied Chemistry Research | Avila M.,University of Castilla - La Mancha
Analytica Chimica Acta | Year: 2012

Micro total analysis (μTAS), also called " lab-on-a-chip (LOC)" technology, promises solutions for high throughput and highly specific analysis for chemistry, biology and medicine, while consuming only tiny amounts of samples, reactants and space. This article reports selected contributions of LOC, which represent clear practical approaches for routine work, or presenting potentiality to be transferred to routine analytical laboratories. Taking into account the present LOC state-of-the-art, we identify various reasons for its scarce implementation in routine analytical laboratories despite its high analytical potential, as well as the probably main " niche" for successfully practical developments is suggested. © 2012 Elsevier B.V..


Lerma-Garcia M.J.,University of Castilla - La Mancha | Lerma-Garcia M.J.,Regional Institute for Applied Chemistry Research | Zougagh M.,Regional Institute for Applied Chemistry Research | Rios A.,University of Castilla - La Mancha | Rios A.,Regional Institute for Applied Chemistry Research
Microchimica Acta | Year: 2013

We have developed a simple method for the extraction of sulfonylurea herbicides (SUHs) from environmental water samples. It is based on a magnetic molecular imprint (MMIP) as a sorbent. The MMIP was prepared using metsulfuron-methyl as the template molecule, methacrylic acid as the functional monomer, trimethylolpropane trimethacrylate as the cross-linking agent, and magnetite as the magnetic component. Extraction can be carried out by blending and stirring water sample, extraction solvent and MMIP. Once the extraction is completed, the MMIP containing the SUHs can be separated from the sample matrix with a magnet. The SUHs desorbed from the polymers were then quantified by capillary liquid chromatography with diode array detection. The limits of quantification are in the range of 0.08 to 0.1 ng mL-1. Repeatabilities of peak areas and retention times range from 2.9 % to 4.0 % and from 0.1 % to 0.3 %, respectively. The method was successfully applied to the determination of the SUHs bensulfuron-methyl, metsulfuronmethyl, pyrazosulfuron-methyl, thifensulfuron-methyl, and triasulfuron in waste water samples. Recoveries range from 94.3 % to 102.3 %. © 2013 Springer-Verlag Wien.

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