title: Trace analysis of sulforaphane in bee pollen and royal jelly by liquid chromatography-tandem mass spectrometry.
abstract: In this study, we investigate for the first time the presence of sulforaphane (SFN) residues in two of the most currently consumed food/dietary supplements, royal jelly and bee pollen. Chromatography-tandem mass spectrometry (LC-MS/MS) was the method employed, the mass spectrometer consisting of an ion-trap mass analyzer used with electrospray ionization (ESI) in positive ion mode. An efficient sample treatment involving a solvent extraction with methanol, centrifugation, and concentration in a rotary evaporator was proposed. In all cases average analyte recoveries were between 92 and 106%. Chromatographic analysis (16min) was performed on a core-shell technology based column (Kinetex C18, 150×4.6mm, 2.6μm, 100Å). The mobile phase consisted of 0.02M ammonium formate in water and acetonitrile, with a flow rate of 0.5mL/min in gradient elution mode. The fully validated method was selective, linear from 8 to 1000μg/kg (bee pollen), or from 10 to 1250μg/kg (royal jelly), precise and accurate; relative standard deviation (% RSD) and relative error (% RE) values were below 10%. Low limits of detection (LOD) and quantification (LOQ) were obtained, namely, 3μg/kg (LOD) and 8 (bee pollen) and 10 (royal jelly) μg/kg (LOQ). The method was applied for SFN analysis in several royal jelly and bee pollen samples. SFN was detected at trace levels in some bee pollen samples (<23μg/kg) examined, whilst SFN went undetected in the royal jelly samples analyzed.
authors.affiliation: IU CINQUIMA, Analytical Chemistry Group, University of Valladolid, 47011 Valladolid, Spain. Electronic address: ana.ares@qa.uva.es.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Ares
authors.affiliation: IU CINQUIMA, Analytical Chemistry Group, University of Valladolid, 47011 Valladolid, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Ayuso
authors.affiliation: IU CINQUIMA, Analytical Chemistry Group, University of Valladolid, 47011 Valladolid, Spain.
authors.forename: José L
authors.initials: JL
authors.lastname: Bernal
authors.affiliation: IU CINQUIMA, Analytical Chemistry Group, University of Valladolid, 47011 Valladolid, Spain.
authors.forename: María J
authors.initials: MJ
authors.lastname: Nozal
authors.affiliation: IU CINQUIMA, Analytical Chemistry Group, University of Valladolid, 47011 Valladolid, Spain. Electronic address: jose.bernal@qa.uva.es.
authors.forename: José
authors.initials: J
authors.lastname: Bernal
mesh_terms: D000818:Animals; D001516:Bees; D002853:Chromatography, Liquid / Q000379:methods*; D005227:Fatty Acids / Q000737:chemistry*; D017879:Isothiocyanates / Q000032:analysis*; D057230:Limit of Detection; D016014:Linear Models; D011058:Pollen / Q000737:chemistry*; D015203:Reproducibility of Results; D013454:Sulfoxides; D053719:Tandem Mass Spectrometry / Q000379:methods*; D000099219:Royal Jelly
chemical_list: D005227:Fatty Acids; D017879:Isothiocyanates; D013454:Sulfoxides; D000099219:Royal Jelly; C016766:sulforaphane
keywords: Bee pollen; Liquid chromatography; Mass spectrometry; Royal jelly; Sulforaphane