Publications by authors named "A Ares"

The simultaneous separation of the enantiomers of six anticoagulant rodenticides, derived from 4-hydroxycoumarin, has been studied in this work. Ten different stationary phases (zwitterionic, Pirkle-type, polysaccharides and macrocyclic antibiotics derivatives) were evaluated by using supercritical fluid chromatography coupled to two different detectors (circular dichroism and mass spectrometry-single quadrupole). The effect of the type of organic modifier and temperature on the chiral separation was investigated, and the best results were obtained with the column Regis S,S-Whelk-O1 at 25 °C when using a gradient elution program with methanol as organic modifier.

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A new analytical method was developed and validated to determine fourteen bisphenols (A, B, C, E, F, M, P, S, Z, AF, AP, BP, FL, PH) in bee pollen using ultra-high-performance liquid chromatography-tandem mass spectrometry. Two different sample treatments were proposed and evaluated: one based on the QuEChERS (quick, easy, cheap, effective, rugged & safe) approach and the other utilizing microextraction with a supramolecular solvent (SUPRAS). In both cases, average analyte recovery ranged between 71 % and 114 %, and the matrix effect was between -45 % and +5 %, although it was not significant when using the QuEChERS-based method (<±20 %).

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A novel method has been proposed to determine nine plasticizers in honey samples by gas chromatography-mass spectrometry. An efficient sample treatment was proposed (average analyte recoveries between 77% and 118%) involving a double solvent extraction with ethyl acetate, followed by a clean-up step with florisil. Chromatographic analysis (< 21 min) was performed in an Agilent HP-5MS column under programmed temperature conditions.

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A new analytical methodology was proposed to determine fourteen bisphenols in honeys from different botanical origins using ultra-high performance liquid chromatography-tandem mass spectrometry. A fast, efficient, environmentally-friendly and simple sample treatment (recoveries between 81% and 116%; matrix effect <20% for all studied compounds except for bisphenol E, F and S) was proposed, which involved a solvent microextraction with acetone and a small volume/amount of 1-hexanol. Chromatographic analysis (< 15 min) was performed in a Kinetex EVO C column under gradient elution mode.

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