0000000000773414
AUTHOR
M. T. Ubeda-torres
showing 2 related works from this author
Effect of sodium dodecyl sulphate and Brij-35 on the analysis of sulphonamides in physiological samples using direct injection and acetonitrile gradi…
2016
Micellar liquid chromatography (MLC) is a reversed-phase (RP) mode, which often does not require gradient elution, since the peaks of mixtures of compounds within a large range of polarities appear more evenly distributed in the chromatograms of isocratic elution, giving rise to a “gradient effect”. However, the use of a gradient of organic solvent may still be convenient to shorten the total analysis time. This work compares the separation of 15 sulphonamides using conventional hydro-organic RPLC and MLC with the surfactants sodium dodecyl sulphate (SDS) and Brij-35, and both isocratic and gradient elution with acetonitrile. The observed behaviour is rationalized attending to the interacti…
Gaining insight in the behaviour of imidazolium-based ionic liquids as additives in reversed-phase liquid chromatography for the analysis of basic co…
2015
In reversed-phase liquid chromatography in the absence of additives, cationic basic compounds give rise to broad and asymmetrical peaks as a result of ionic interactions with residual free silanols on silica-based stationary phases. Ionic liquids (ILs), added to the mobile phase, have been suggested as alternatives to amines to block the activity of silanols. However, the dual character of ILs should be considered: both cation and anion may be adsorbed on the stationary phase, thereby creating a double asymmetrical layer positively or negatively charged, depending on the relative adsorption of both ions. In this work, a study of the performance of six imidazolium-based ILs (the chlorides an…