M.C. García-Alvarez-Coque
University of Valencia
MicelleAnalytical chemistrySelectivityDetection limitWork (thermodynamics)DeconvolutionHigh-performance liquid chromatographyCationic polymerizationChemistryAcetonitrileSilanolSodium dodecyl sulfateSolventPhase compositionReagentChromatographyPhase (matter)Reversed-phase chromatographyMicellar electrokinetic chromatographyMicellar liquid chromatographySodiumPulmonary surfactantElutionResolution (mass spectrometry)
147Publications
31H-index
2,573Citations
Publications 147
Newest
#1A. Gisbert-Alonso (University of Valencia)H-Index: 1
#2J.A. Navarro-Huerta (University of Valencia)H-Index: 6
Last. M.C. García-Alvarez-Coque (University of Valencia)H-Index: 31
view all 4 authors...
Abstract The resolution of samples containing unknown compounds of different nature, or without standards available, as is the case of chromatographic fingerprints, is still a challenge. Possibly, the most problematic aspect that prevents systematic method development is finding models that describe without bias the retention behaviour of the compounds in the samples. In this work, the use of global models (able to describe the whole sample) is proposed as an alternative to the use of individual...
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#1N. Pankajkumar-Patel (University of Valencia)H-Index: 1
#2E. Peris-García (University of Valencia)H-Index: 5
Last. M.C. García-Alvarez-Coque (University of Valencia)H-Index: 31
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Abstract Basic compounds yield long retention times and broad and asymmetric peaks in reversed-phase liquid chromatography, due to interaction with residual silanols in the columns. The addition of the surfactant sodium dodecyl sulphate in the so called micellar liquid chromatography enhances the efficiency, but long retention is achieved, due to electrostatic interaction between the cationic species of basic compounds and the anionic sulphate group of the surfactant. This forces the addition of...
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#1N. Pankajkumar-Patel (University of Valencia)H-Index: 1
#2E. Peris-García (University of Valencia)H-Index: 5
Last. M.C. García-Alvarez-Coque (University of Valencia)H-Index: 31
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Abstract The capability of liquid chromatography with microemulsions (MEs) as mobile phases was studied for the analysis of four parabens (butylparaben, ethylparaben, methylparaben, and propylparaben) and seven β-adrenoceptor antagonists (acebutolol, atenolol, carteolol, metoprolol, oxprenolol, propranolol, and timolol). MEs were formed by mixing aqueous solutions of the anionic surfactant sodium dodecyl sulphate, the alcohol 1-butanol that played the role of co-surfactant, and octane as oil. In...
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#1Mireia Perez-Baeza (University of Valencia)H-Index: 2
#2Laura Escuder-Gilabert (University of Valencia)H-Index: 19
Last. M.C. García-Alvarez-Coque (University of Valencia)H-Index: 31
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Abstract The description of the profiles of chromatographic peaks has been studied extensively, with a large number of proposed mathematical functions. Among them, the accuracy achieved with modified Gaussian models that describe the deviation of an ideal Gaussian peak as a change in the peak variance or standard deviation over time, has been highlighted. These models are, in fact, a family of functions of different complexity with great flexibility to adjust chromatographic peaks over a wide ra...
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#1J.A. Navarro-Huerta (University of Valencia)H-Index: 6
#2A. Gisbert-Alonso (University of Valencia)H-Index: 1
Last. M.C. García-Alvarez-Coque (University of Valencia)H-Index: 31
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Abstract The basis of interpretive optimisation in liquid chromatography is the prediction of resolution, from appropriate solute retention models. The reliability of the process depends critically on the quality of the experimental design. This work develops, validates and applies a general methodology aimed to evaluate the quality of any training experimental design, which will be applied in Part II to design optimisation. The methodology is based on the systematic evaluation of the uncertaint...
1 CitationsSource
#1María Vergara-Barberán (University of Valencia)H-Index: 9
#2J.A. Navarro-Huerta (University of Valencia)H-Index: 6
Last. M.C. García-Alvarez-Coque (University of Valencia)H-Index: 31
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Abstract The development of a new comprehensive two-dimensional liquid chromatographic method is described, to obtain the profiles of polyphenolic compounds present in olive (Olea europaea L.) leaves and pulps from different genetic origin. Optimisation of the stationary phase nature, particle size, column length and internal diameter, as well as other separation conditions, was performed. Along the study, three stationary phases (C18, PFP and phenyl) in the first dimension (1D), and five (C18, ...
1 CitationsSource
#1Nikitaben Pankajkumar-Patel (University of Valencia)H-Index: 1
#2E. Peris-García (University of Valencia)H-Index: 5
Last. M.C. García-Alvarez-Coque (University of Valencia)H-Index: 31
view all 4 authors...
In reversed-phase liquid chromatography (RPLC), basic drugs are positively charged at the usual working pH range and interact with free anionic silanols present in conventional silica based stationary phases, which is translated in stronger retention and tailed and broad peaks. This problem can be solved by addition to the mobile phase of reagents that are adsorbed on the stationary phase, avoiding the access of solutes to silanols. Among these additives, surfactants under micellar conditions ha...
2 CitationsSource
#1J.A. Navarro-Huerta (University of Valencia)H-Index: 6
#2A.G. Vargas-García (University of Valencia)
Last. M.C. García-Alvarez-Coque (University of Valencia)H-Index: 31
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Abstract Micellar liquid chromatography (MLC) is a reversed-phase mode with mobile phases containing an organic solvent and a micellised surfactant. Most procedures developed in MLC are implemented in the isocratic mode, since the general elution problem in chromatography is less troublesome. However, gradient elution may be still useful in MLC to analyse mixtures of compounds within a wide range of polarities, in shorter times. MLC using gradients is attractive to determine by direct injection ...
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#1Juan José Baeza-Baeza (University of Valencia)H-Index: 19
#2M.C. García-Alvarez-Coque (University of Valencia)H-Index: 31
Abstract Modelling the retention behaviour of solutes in liquid chromatography, based on the composition of the mobile phase is a common task in the chromatographic practice. Along the development of liquid chromatography (LC), several models have been proposed to help in understanding the retention mechanisms, and especially, allow the prediction of retention times with optimisation purposes. Particular models are used for different LC modes, such as normal phase (NPLC), reversed phase (RPLC), ...
2 CitationsSource
#1Juan José Baeza-Baeza (University of Valencia)H-Index: 19
#2M.C. García-Alvarez-Coque (University of Valencia)H-Index: 31
Abstract Gradient elution in liquid chromatography reduces the analysis time, improves the efficiency and increases the peak capacity. The study of this chromatographic mode has been based mainly on kinetic dispersion models. The plate model has been applied to a lesser extent, despite being the basis for the concepts of plate height and chromatographic efficiency. In this work, a general equation describing peak dispersion in HPLC gradient elution is derived from the plate model. This equation ...
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