Quantification of isoflavones in coffee by using solid phase extraction (SPE) and high‐performance liquid chromatography–tandem mass spectrometry (HPLC‐MS/MS). (25th August 2016)

• Record Type: Journal Article
• Authors: Caprioli, Giovanni; Navarini, Luciano; Cortese, Manuela; Ricciutelli, Massimo; Torregiani, Elisabetta; Vittori, Sauro; Sagratini, Gianni
• Other Names: Giorgi Gianluca guestEditor.
• Is Part Of: Journal of mass spectrometry. Volume 51:Number 9(2016)
• Page Start: 698
• Page End: 703
• Publication Date: 2016-08-25
• Subjects: coffee -- bioactives -- isoflavones -- SPE -- HPLC‐MS/MS; Mass spectrometry -- Periodicals; 543.65
• DOI: 10.1002/jms.3802
• Languages: English
• ISSNs: 1076-5174

Abstract

Abstract : A new method for extracting isoflavones from espresso coffee (EC) was coupled with high‐performance liquid chromatography–tandem mass spectrometry (MS/MS) for the first time to analyse five isoflavones, which included both a glycosilated form, genistin and the aglycons daidzein, genistein, formononetin and biochanin A. Isoflavones were extracted from coffee samples using methanol, stored in a freezer overnight to precipitate proteic or lipidic residues and purified on SPE C18 cartridges before high‐performance liquid chromatography–MS/MS analysis. The recovery percentages obtained by spiking the matrix at concentrations of 10 and 100 µg l −1 with a standard mixture of isoflavones were in the range of 70 to 104%. The limits of detection and limits of quantification were in the range of 0.015–0.3 µg l −1 and 0.05–1 µg l −1, respectively. Once validated, the method was used to analyze the concentrations of isoflavones in six ECs and ten ground coffee samples. Only formononetin and biochanin A were found, and their respective concentrations ranged from 0.36 to 0.41 µg l −1 and from 0.58 to 3.26 µg l −1 in ECs and from 0.36 to 4.27 µg kg −1 and from 0.71 to 3.95 µg kg −1 in ground coffees. This method confirms the high specificity and selectivity of MS/MS systems for detecting bioactives in complex matrices such as coffee.Copyright © 2016 John Wiley & Sons, Ltd.