Improved Separation of Intact Glucosinolates in Bee Pollen by Using Ultra-High-Performance Liquid Chromatography Coupled to Quadrupole Time-of-Flight Mass Spectrometry
A method to determine 15 intact glucosinolates (epiprogoitrin; glucoalyssin; glucobrassicanapin; glucobrassicin; glucoerucin; glucoiberin; gluconapin; gluconasturtiin; glucoraphanin; glucotropaeolin; 4-hydroxyglucobrassicin; 4-methoxyglucobrassicin; neoglucobrassicin; progoitrin; sinigrin) in bee pollen has been proposed, by means of ultra-high liquid chromatography coupled to a quadrupole time-of-flight mass detector. Efficient sample treatment (with average analyte recoveries between 80 and 96%) involving a solid-liquid extraction with hot water, followed by solid-phase extraction with a weak anion exchange sorbent (NH2), was employed to analyze those intact glucosinolates in bee pollen. Chromatographic analysis (15 min) was performed on a fully porous silica–based column (Luna® Omega C18) with a mobile phase composed of a mixture of acetonitrile (0.1% formic acid) and water (0.1% formic acid) in gradient elution mode at a flow rate of 0.2 mL/min. Accordingly, the analytical performance of the proposed method was evaluated, and it was then applied to determine intact glucosinolates in commercial bee pollen samples from different Spanish regions. Ten intact glucosinolates were identified in certain samples over a wide concentration range.
KeywordsBee pollen Glucosinolates Solid-liquid extraction Solid-phase extraction UHPLC-QTOF
The authors wish to thank David Rixham (White Rose English School, Valladolid, Spain) for performing the English revision and the “Laboratorio de Técnicas Instrumentales” (University of Valladolid) for using its UHPLC-QTOF system.
This work was funded by Project RTA2015-00013-C03-03.
Compliance with Ethical Standards
Conflict of Interest
José Bernal declares that he has no conflict of interest. David González declares that he has no conflict of interest. Silvia Valverde declares that she has no conflict of interest. Laura Toribio declares that she has no conflict of interest. Ana M. Ares declares that she has no conflict of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
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