Axel Andrés
University of Barcelona
AnalyteAnalytical chemistryAmine gas treatingBase (chemistry)Work (thermodynamics)Column (database)SolubilityCarry (arithmetic)Van Deemter equationAqueous solutionChemistryPartition coefficientIonizationLipophilicityStandard deviationAcetonitrileCarboxylic acidMethanolCharacterization (materials science)Phase compositionUltra high pressureExperimental workAqueous solubilityShake flaskProtonationGradient elutionMeasurement methodField (computer science)Partition (number theory)ChromatographyPhase (matter)Reversed-phase chromatographyElution
5Publications
5H-index
113Citations
Publications 5
Newest
#1Axel Andrés (University of Barcelona)H-Index: 5
#2Ken Broeckhoven (Vrije Universiteit Brussel)H-Index: 21
Last. Gert Desmet (Vrije Universiteit Brussel)H-Index: 56
view all 3 authors...
Due to the developing insights in the theory of chromatography, column manufacturers of any kind (industrial, academic) nowadays have a broad array of experimental column testing tools at their disposal. The present tutorial aims at helping the novice in the field getting an overview of these tools and provides a fixed procedure to carry out the subsequent steps in the column quality analysis (guided via an Excel template file). After some brief introduction about the main equations, the reader ...
15 CitationsSource
#1Axel Andrés (University of Barcelona)H-Index: 5
#2Martí Rosés (University of Barcelona)H-Index: 58
Last. Josep M. HuertaH-Index: 7
view all 7 authors...
Abstract Several procedures based on the shake-flask method and designed to require a minimum amount of drug for octanol–water partition coefficient determination have been established and developed. The procedures have been validated by a 28 substance set with a lipophilicity range from −2.0 to 4.5 (log D 7.4 ). The experimental partition is carried out using aqueous phases buffered with phosphate (pH 7.4) and n-octanol saturated with buffered water and the analysis is performed by liquid chrom...
62 CitationsSource
#1Axel Andrés (University of Barcelona)H-Index: 5
#2Martí Rosés (University of Barcelona)H-Index: 58
Last. Elisabeth Bosch (University of Barcelona)H-Index: 58
view all 3 authors...
Abstract Retention of ionizable analytes under gradient elution depends on the pH of the mobile phase, the p K a of the analyte and their evolution along the programmed gradient. In previous work, a model depending on two fitting parameters was recommended because of its very favorable relationship between accuracy and required experimental work. It was developed using acetonitrile as the organic modifier and involves p K a modeling by means of equations that take into account the acidic functio...
6 CitationsSource
#1Axel Andrés (University of Barcelona)H-Index: 5
#2Martí Rosés (University of Barcelona)H-Index: 58
Last. Elisabeth Bosch (University of Barcelona)H-Index: 58
view all 3 authors...
Abstract In previous work, a two-parameter model to predict chromatographic retention of ionizable analytes in gradient mode was proposed. However, the procedure required some previous experimental work to get a suitable description of the p K a change with the mobile phase composition. In the present study this previous experimental work has been simplified. The analyte p K a values have been calculated through equations whose coefficients vary depending on their functional group. Forced by thi...
7 CitationsSource
#1Axel Andrés (University of Barcelona)H-Index: 5
#2Adolfo Téllez (University of Barcelona)H-Index: 5
Last. Elisabeth Bosch (University of Barcelona)H-Index: 58
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Abstract The retention of an ionizable analyte under RP-HPLC organic modifier gradient elution is strongly affected by its ionization degree which, in turn, depends on its p K a and on the pH of the mobile phase. The values of both parameters change depending on the mobile phase composition and thus retention becomes a parameter quite difficult to predict, particularly when working in gradient mode. In this work, an equation describing the retention of ionizable analytes has been combined with t...
18 CitationsSource