ENCARNACIÓN RODRÍGUEZ GONZALO - Academia.edu (original) (raw)
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Papers by ENCARNACIÓN RODRÍGUEZ GONZALO
Analusis, 1991
Infrared spectroscopic studies revealed that the herbicide Pyrazon (5-amino-chloro-2-phenyl-3(2H)... more Infrared spectroscopic studies revealed that the herbicide Pyrazon (5-amino-chloro-2-phenyl-3(2H)-pyridazinone) is in acid-base equilibrium with a form produced by acid hydrolysis of the >C=N- bond, which in turn involves the reversible opening of the pyridazine ring. The acid-base constant of this equilibrium could not be calculated by spectroscopic or potentiometric methods; the polarographic dissociation constant, pK' a , could only be determined by polarographic studies in different buffers
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Toxicological & Environmental Chemistry, 1993
Montmorillonites modified with tetradecyltrimethylammonium and trimethylphenyl ammonium and the h... more Montmorillonites modified with tetradecyltrimethylammonium and trimethylphenyl ammonium and the hydroxy‐Al polymer were studied as sorbents for organophosphorus pesticides parathion and paraoxon in aqueous media. Sorptive characteristics of modified‐clays depend on their organic carbon content and the hydrophobic nature of the pesticide. Hydroxy‐Al‐montmorillonite showed a weak capacity for adsorption of both pesticides. In contrast, tetradecyltrimethylammonium‐montmorillonite appears to be an effective sorbent for removing hydrophobic pesticides from water and this fact can be applied for contamination prevention or decontamination of sediments and waters.
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Journal of Chromatography A, 1996
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Journal of Chromatography A, 1991
ABSTRACT A liquid chromatographic method has been developed for the determination of acephate in ... more ABSTRACT A liquid chromatographic method has been developed for the determination of acephate in aqueous extracts of agriculture soils. Aqueous extracts of spiked soil samples were used. The lower detection limit was 1 μg/ml; the relative standard deviation for repeatability (R.S.D.) based on peak area measurement ranged from 0.2 to 4.5%. Recoveries from spiked samples ranged from 93.6 to 104.3%. The method used a C18 reversed-phase column, a mobile phase of 5% (v/v) methanol-water and UV detection at 215 nm. The application of the proposed method to the study of the adsorption of acephate in aqueous medium by a selected group of soils yielded satisfactory results.
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Analytica Chimica Acta, 1995
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Capillary electrophoresis was applied to the analysis of a mixture of triazine herbicides of envi... more Capillary electrophoresis was applied to the analysis of a mixture of triazine herbicides of environmental interest. Micellar electrokinetic capillary chromatography (MECC) proved to be satisfactory for the separation of triazines, providing high efficiency in short analysis times. Several electrophoretic parameters were investigated: injection conditions, pH and buffer concentration, surfactant concentration and applied voltage. The optimized MECC method was applied to the determination of these compounds in water samples; using a solid-phase concentration step, herbicide concentrations lower than 0.2 ng/ml can be measured, the relative standard deviations being about 20%.
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Analytica Chimica Acta, 1996
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Journal of Electroanalytical Chemistry and Interfacial Electrochemistry, Apr 1, 1988
ABSTRACT
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Journal of Chromatography A, 1996
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… of Chromatography A, 1992
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Microchemical Journal
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Microchemical Journal
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Talanta
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Comprehensive Reviews in Food Science and Food Safety
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Journal of Chromatography A
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TrAC Trends in Analytical Chemistry
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Food Chemistry
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Egg Innovations and Strategies for Improvements, 2017
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Food Chemistry, 2016
In this work we propose a rapid and efficient method for the joint determination of nucleosides a... more In this work we propose a rapid and efficient method for the joint determination of nucleosides and nucleotides in dairy and non-dairy baby foods based on hydrophilic interaction chromatography coupled to tandem mass spectrometry in the presence of diethylammonium (DEA) as a hydrophilic ion-pairing reagent (IP-HILIC-MS/MS). Sample treatment of the baby food included dilution with water and centrifugal ultrafiltration (CUF) with an additional washing step that notably improved the global performance of the process. Later dilution of the extract with acetonitrile allowed adequate separation in the HILIC system. With the proposed treatment, we obtained extraction recoveries higher than 80% and, additionally, no matrix effects were observed. The CUF-IP-HILIC-MS/MS method was validated according to the 2002/657/EC decision and was used for the quantification of nucleotides and nucleosides in sixteen samples of commercial baby foods.
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Journal of Chromatography a, Mar 1, 2000
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Analusis, 1991
Infrared spectroscopic studies revealed that the herbicide Pyrazon (5-amino-chloro-2-phenyl-3(2H)... more Infrared spectroscopic studies revealed that the herbicide Pyrazon (5-amino-chloro-2-phenyl-3(2H)-pyridazinone) is in acid-base equilibrium with a form produced by acid hydrolysis of the >C=N- bond, which in turn involves the reversible opening of the pyridazine ring. The acid-base constant of this equilibrium could not be calculated by spectroscopic or potentiometric methods; the polarographic dissociation constant, pK' a , could only be determined by polarographic studies in different buffers
Bookmarks Related papers MentionsView impact
Toxicological & Environmental Chemistry, 1993
Montmorillonites modified with tetradecyltrimethylammonium and trimethylphenyl ammonium and the h... more Montmorillonites modified with tetradecyltrimethylammonium and trimethylphenyl ammonium and the hydroxy‐Al polymer were studied as sorbents for organophosphorus pesticides parathion and paraoxon in aqueous media. Sorptive characteristics of modified‐clays depend on their organic carbon content and the hydrophobic nature of the pesticide. Hydroxy‐Al‐montmorillonite showed a weak capacity for adsorption of both pesticides. In contrast, tetradecyltrimethylammonium‐montmorillonite appears to be an effective sorbent for removing hydrophobic pesticides from water and this fact can be applied for contamination prevention or decontamination of sediments and waters.
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Journal of Chromatography A, 1996
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Journal of Chromatography A, 1991
ABSTRACT A liquid chromatographic method has been developed for the determination of acephate in ... more ABSTRACT A liquid chromatographic method has been developed for the determination of acephate in aqueous extracts of agriculture soils. Aqueous extracts of spiked soil samples were used. The lower detection limit was 1 μg/ml; the relative standard deviation for repeatability (R.S.D.) based on peak area measurement ranged from 0.2 to 4.5%. Recoveries from spiked samples ranged from 93.6 to 104.3%. The method used a C18 reversed-phase column, a mobile phase of 5% (v/v) methanol-water and UV detection at 215 nm. The application of the proposed method to the study of the adsorption of acephate in aqueous medium by a selected group of soils yielded satisfactory results.
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Analytica Chimica Acta, 1995
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Capillary electrophoresis was applied to the analysis of a mixture of triazine herbicides of envi... more Capillary electrophoresis was applied to the analysis of a mixture of triazine herbicides of environmental interest. Micellar electrokinetic capillary chromatography (MECC) proved to be satisfactory for the separation of triazines, providing high efficiency in short analysis times. Several electrophoretic parameters were investigated: injection conditions, pH and buffer concentration, surfactant concentration and applied voltage. The optimized MECC method was applied to the determination of these compounds in water samples; using a solid-phase concentration step, herbicide concentrations lower than 0.2 ng/ml can be measured, the relative standard deviations being about 20%.
Bookmarks Related papers MentionsView impact
Analytica Chimica Acta, 1996
Bookmarks Related papers MentionsView impact
Journal of Electroanalytical Chemistry and Interfacial Electrochemistry, Apr 1, 1988
ABSTRACT
Bookmarks Related papers MentionsView impact
Journal of Chromatography A, 1996
Bookmarks Related papers MentionsView impact
… of Chromatography A, 1992
Bookmarks Related papers MentionsView impact
Microchemical Journal
Bookmarks Related papers MentionsView impact
Microchemical Journal
Bookmarks Related papers MentionsView impact
Talanta
Bookmarks Related papers MentionsView impact
Comprehensive Reviews in Food Science and Food Safety
Bookmarks Related papers MentionsView impact
Journal of Chromatography A
Bookmarks Related papers MentionsView impact
TrAC Trends in Analytical Chemistry
Bookmarks Related papers MentionsView impact
Food Chemistry
Bookmarks Related papers MentionsView impact
Egg Innovations and Strategies for Improvements, 2017
Bookmarks Related papers MentionsView impact
Food Chemistry, 2016
In this work we propose a rapid and efficient method for the joint determination of nucleosides a... more In this work we propose a rapid and efficient method for the joint determination of nucleosides and nucleotides in dairy and non-dairy baby foods based on hydrophilic interaction chromatography coupled to tandem mass spectrometry in the presence of diethylammonium (DEA) as a hydrophilic ion-pairing reagent (IP-HILIC-MS/MS). Sample treatment of the baby food included dilution with water and centrifugal ultrafiltration (CUF) with an additional washing step that notably improved the global performance of the process. Later dilution of the extract with acetonitrile allowed adequate separation in the HILIC system. With the proposed treatment, we obtained extraction recoveries higher than 80% and, additionally, no matrix effects were observed. The CUF-IP-HILIC-MS/MS method was validated according to the 2002/657/EC decision and was used for the quantification of nucleotides and nucleosides in sixteen samples of commercial baby foods.
Bookmarks Related papers MentionsView impact
Journal of Chromatography a, Mar 1, 2000
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