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ABSTRACT: For the first time, an electromembrane extraction combined with a HPLC procedure using diode array and fluorescence detection has been developed for the determination of seven widely used fluoroquinolones (FQs): marbofloxacin, norfloxacin, ciprofloxacin, danofloxacin, enrofloxacin, gatifloxacin and grepafloxacin. The drugs were extracted from acid aqueous sample solutions (pH 5), through a supported liquid membrane consisting of 1-octanol impregnated in the walls of a S6/2 Accurel® polypropylene hollow fiber, to an acid (pH 2) aqueous acceptor solution inside the lumen of the hollow fiber. The main operational parameters were optimized, and extractions were carried out in 15 min using a potential of 50 V. Enrichment factors of 40-85 have been obtained using only 15 min of extraction time versus 330 min used in a previously proposed hollow-fiber liquid-phase microextraction procedure. The procedure allows low detection and quantitation limits of 0.005-0.07 and 0.007-0.15 μg L(-1), respectively. The proposed method was successfully applied to the FQs analysis in urban wastewaters.
Analytical and Bioanalytical Chemistry 01/2013; · 3.78 Impact Factor
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ABSTRACT: This work proposes for the first time the use of a three phase hollow fiber liquid phase microextraction (HF-LPME) procedure for the extraction, and the later HPLC determination using fluorescence detection, of two much known endocrine disrupting compounds (EDCs): n-octylphenol (OP) and n-nonylphenol (NP). The extraction was carried out through a dihexyl ether liquid membrane supported on an Accurel® Q3/2 polypropylene hollow fiber. Optimum pH for donor and acceptor phases and extraction time were established. Enrichment (preconcentration) factors of 50 were obtained that allows detection limits of 0.54 and 0.52ngmL(-1) for OP and NP, respectively. The method was successfully applied to the determination of these EDCs in environmental water samples, including urban wastewaters.
Science of The Total Environment 11/2012; 443C:1-6. · 3.29 Impact Factor
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ABSTRACT: This work proposes for the first time the use of a three phase hollow fiber liquid phase microextraction (HF-LPME) procedure for the simultaneous extraction, and the later HPLC determination, of some phenol substituting compounds (alkyl-, chloro- and nitrophenols) that are considered as highly toxic compounds and/or endocrine disrupting ones. The substances studied include four chlorophenols (CPs): 2,4-dichlorophenol (2,4-DCP), 2,5-dichlorophenol (2,5-DCP), 2,6-dichlorophenol (2,6-DCP) and pentachlorophenol (PCP), three nitrophenols (NPs): 2,4-dinitrophenol (2,4-DNP), 2,5-dinitrophenol (2,5-DNP) and 2,6-dinitriphenol (2,6-DNP) and two alkylphenols (APs): tert butylphenol (TBP) and sec butylphenol (SBP). The extraction was carried out through a dihexyl ether liquid membrane supported on an Accurel(®) Q3/2 polypropylene hollow fiber. Optimum pH for donor and acceptor phases and extraction time were established. The enrichment (preconcentration) factors obtained were between 30 and 700 that allows detection limits between 140 and 290pgmL(-1). The method was successfully applied to the determination of the compounds in environmental water samples, including urban wastewaters.
Talanta 09/2012; 99:55-61. · 3.79 Impact Factor
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Analytical Letters 05/2012; 45(8):804-830. · 1.02 Impact Factor
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ABSTRACT: The presence of pharmaceuticals in the environment due to growing worldwide consumption has become an important problem that requires analytical solutions. This paper describes a CE determination for several nonsteroidal anti-inflammatory drugs (ibuprofen, naproxen, ketoprofen, diclofenac, ketorolac, aceclofenac and salicylic acid) in environmental waters using hollow fiber membrane liquid-phase microextraction. The extraction was carried out using a polypropylene membrane supporting dihexyl ether and the electrophoretic separation was performed in acetate buffer (30 mM, pH 4) using ACN as the organic modifier. Detection limits between 0.25 and 0.86 ng/mL were obtained, respectively. The method could be applied to the direct determination of the seven anti-inflammatories in wastewaters, and five of them have been determined or detected in different urban wastewaters.
Electrophoresis 08/2011; 32(16):2107-13. · 3.30 Impact Factor
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ABSTRACT: In this paper, an electromembrane extraction (EME) combined with a HPLC procedure using diode array (DAD) and fluorescence detection (FLD) has been developed for the determination of six widely used non-steroidal anti-inflammatory drugs (NSAIDs): salicylic acid (SAC), ketorolac (KTR), ketoprofen (KTP), naproxen (NAX), diclofenac (DIC) and ibuprofen (IBU). The drugs were extracted from basic aqueous sample solutions, through a supported liquid membrane (SLM) consisting of 1-octanol impregnated in the walls of a S6/2 Accurel(®) polypropylene hollow fiber, and into a basic aqueous acceptor solution resent inside the lumen of the hollow fiber with a potential difference of 10 V applied over the SLM. Extractions that were carried out in 10 min using a potential of 10 V from pH 12 NaOH aqueous solutions shown concentration enrichments factors of 28-49 in a pH 12 NaOH aqueous acceptor solution. The proposed method was successfully applied to urban wastewaters. Excellent selectivity was demonstrated as no interfering peaks were detected. The procedure allows very low detection and quantitation limits of 0.0009-9.0 and 0.003-11.1 μg L(-1), respectively.
Talanta 07/2011; 85(1):394-9. · 3.79 Impact Factor
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ABSTRACT: In this paper, a three phase hollow fiber-based liquid phase microextraction (HF-LPME) combined with a HPLC procedure using diode array (DAD) and fluorescence detection (FLD) has been developed for the determination of eight widely used fluoroquinolones: marbofloxacin (MRB), norfloxacin (NRF), ciprofloxacin (CPR), danofloxacin (DNF), enrofloxacin (ENR), gatifloxacin (GTF), grepafloxacin (GRP) and flumequine (FLM). A Q3/2 Accurel PP polypropylene hollow fiber supporting 1-octanol was used between a 2 M Na2SO4 aqueous solution (pH 7) as donor phase and aqueous solution (pH 12) as acceptor phase. The microextraction parameters were optimised from an experimental central composite design. The procedure allows very low detection and quantitation limits of 0.3-16 ng L(-1) and 1-50 ng L(-1), respectively. The proposed method was applied to the determination of the analytes in bovine urine and in environmental water samples (surface, tap and wastewater).
Journal of pharmaceutical and biomedical analysis 02/2011; 55(2):332-41. · 2.45 Impact Factor
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ABSTRACT: In this paper, three phase-hollow fiber-based liquid phase microextraction (HF-LPME) combined with a HPLC procedure using diode array (DAD) and fluorescence detection (FLD) has been developed for the determination of four widely used sulfonamides: sulfadiazine, sulfamerazine, sulfamethazine, sulfamethoxazole and their main metabolites, the corresponding N(4)-acetyl derivatives: N(4)-acetyl-sulfadiazine, N(4)-acetyl-sulfamerazine, N(4)-acetyl-sulfamethazine, N(4)-acetyl-sulfamethoxazole. A Q3/2 Accurel KM polypropylene hollow fiber supporting 1-octanol was used between a 2 M Na(2)SO(4) aqueous solution (pH 4) as a donor phase and aqueous solution (pH 12) as an acceptor phase. The procedure allows very low detection and quantitation limits of 0.3-33 ng L(-1) and 0.9-100 ng L(-1), respectively. The proposed method was applied to the determination of the analytes in environmental water samples (surface, tap and wastewater).
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 01/2011; 879(2):197-204. · 2.78 Impact Factor
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ABSTRACT: A simple, rapid and sensitive chemiluminescence method for the determination of sulfite has been developed by combining flow-injection analysis and its sensitizing effect on the known chemiluminescence emission produced by the oxidation of luminol in alkaline medium; in this work permanganate has been proposed as oxidizing reactive. The optimum conditions for the chemiluminescence emission were established. The chemiluminescence was proportional to the sulfite concentration over the range 1.6 × 10(-5) and 4.0 × 10(-4)mol L(-1). The detection limit was 4.7 × 10(-6)mol L(-1) of sulfite. The method has been satisfactorily used for the determination of free and bound sulfite in wines.
Talanta 10/2010; 82(5):2003-6. · 3.79 Impact Factor
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ABSTRACT: The presence of pharmaceuticals in the environment is a very important problem that requires analytical solutions. The wide variety of matrices and, usually, the low pharmaceuticals levels in the environmental samples requires high sensitive and selective analytical procedures. Wastewaters are one of the more important sources of environmental pollutants but they are very complex matrices that need clean-up procedures prior the analysis. Hollow fiber-based liquid-phase microextraction (HF-LPME) is a relatively new technique used in analytical chemistry for sample pre-treatment that offers high selectivity and sensitivity compared to most traditional extraction techniques. The low organic solvent consumption derived from the use of HF-LPME is according to the current trends to a "Green Chemistry", and Analytical Chemistry should follow these environmental good practices. This paper describes an extraction method using a polypropylene membrane supporting dihexyl ether (three-phase hollow fiber-based liquid-phase microextraction (HF-LPME)) for the direct analysis of three pharmaceuticals (salicylic acid (SAC), ibuprofen (IBU) and diclofenac (DIC)) in raw and treated wastewaters followed by a HPLC/MS-MS determination using a highly packed Pursuit XRs Ultra 2.8 microm C18 column that allows high resolution using low flow-rates and, simultaneously, short retention times. Detection limits were 20, 100 and 300 ng L(-1) for salicylic acid, diclofenac and ibuprofen, respectively.
Talanta 07/2010; 82(2):854-8. · 3.79 Impact Factor
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ABSTRACT: This paper describes an extraction method using a polypropylene membrane supporting dihexyl ether (three-phase hollow fiber-based liquid phase microextraction (HF-LPME)) for the analysis of several pharmaceuticals (salicylic acid (SAC), ibuprofen (IBU) and diclofenac (DIC)) followed by a HPLC determination using a monolithic silica type HPLC column, that allows lower retention times than the usual packed columns with adequate resolution. Detection was realized by means of a coupled in series diode array (DAD) and fluorescence (FLD) detectors. HF-LPME is a relatively new technique employed in analytical chemistry for sample pretreatment which offers more selectivity and sensitivity than any traditional extraction technique. Detection limits by DAD are 12, 53 and 40 ng mL(-1) for salicylic acid, diclofenac and ibuprofen, respectively and by FLD 7 and 2 ng mL(-1) for salicylic acid, and ibuprofen. The method has been successfully applied to their direct determination in human urine and the results obtained demonstrated that could be also applied to the determination of the corresponding metabolites.
Analytica chimica acta 10/2009; 653(2):184-90. · 4.31 Impact Factor
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ABSTRACT: Hollow fiber-based liquid-phase microextraction (HF-LPME) is a relatively new technique employed in analytical chemistry for sample pretreatment which offers more selectivity and sensitivity than any traditional extraction technique. This paper describes a three-phase HF-LPME method for ibuprofen using a polypropylene membrane supporting dihexyl ether followed by a chemiluminescence (CL) determination using the CL enhancement on the acidic permanganate-sulfite system in a FIA configuration which is the first time that both techniques have been combined for analytical purposes. The CL intensity (peak area) was proportional to the log of ibuprofen concentration in the donor phase over the range 0.1-20 microg mL(-1). The detection limit was 0.03 microg mL(-1) of ibuprofen in the donor phase. The method was satisfactory reproducible and has been applied to the ibuprofen determination in pharmaceuticals and in real human urine samples.
Talanta 09/2009; 79(3):911-5. · 3.79 Impact Factor
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Analytical Letters 07/2009; 42(10):1471-1478. · 1.02 Impact Factor
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ABSTRACT: Eleven elements (Zn, P, B, Mn, Mg, Cu, Ca, Ba, Sr, Na and K) were determined by inductively plasma coupled spectrometry in 40 honey samples from different places of Spain and four different botanical origins: Eucalyptus (Eucalyptus sp.), Heather (Erica sp.), Orange-blossom (Citrus sinensis) and Rosemary (Rosmarinus officinalis). K, Ca and P show the higher levels with average concentrations ranged between 434.1-1935mgkg(-1) for K; 42.59-341.0mgkg(-1) for Ca and 51.17-154.3mgkg(-1) for P. Levels of Cu (0.531-2.117mgkg(-1)), Ba (0.106-1.264mgkg(-1)) and Sr (0.257-1.462mgkg(-1)) are the lowest in all honey samples. Zn (1.332-7.825mgkg(-1)), Mn (0.133-9.471mgkg(-1)), Mg (13.26-74.38mgkg(-1)) and Na (11.69-218.5mgkg(-1)) concentrations were found strongly dependent on the kind of botanical origin. Results were submitted to pattern recognition procedures, unsupervised methods such as cluster and principal components analysis and supervised learning methods like linear discriminant analysis in order to evaluate the existence of data patterns and the possibility of differentiation of Spanish honeys from different botanical origins according to their mineral content. Cluster analysis shows four clusters corresponding to the four botanical origins of honey and PCA explained 71% of the variance with the first two PC variables. The best-grouped honeys were those from heather; eucalyptus honeys formed a more dispersed group and finally orange-blossom and rosemary honeys formed a less distinguishable group.
Talanta 03/2005; 65(3):686-91. · 3.79 Impact Factor
