Simultaneous determination of steviol and steviol glycosides by liquid chromatography-mass spectrometry

A direct, versatile method for the determination of steviol and nine steviol glycosides in food products has been developed by using electrospray ionisation liquid chromatography-mass spectrometry in the negative-ion mode. Ten stevia compounds were readily separated on an amino column by using a gradient separation. Data for analyte quantification were collected in the selected ion monitoring mode, giving the method limit of detection of 0.01–0.34 µg g−1 and repeatability at the limit of quantitation of 2%–15% relative standard deviation. Thirty-four commercially available food products were tested by using the optimised method, and in these products rebaudioside A and stevioside comprised 52%–100% of the total steviol glycosides. Multiple reaction monitoring data were collected to provide analyte confirmation. Stability data for rebaudioside A stored at room temperature, 40°C and 60°C over a period of 1–14 days are shown.