Simultaneous determination of steviol glycosides in food from stevia by liquid chromatography tandem mass spectrometry (LC-MS/MS)

The objective of this study is to develop a method for determination of steviol glycosides in food using liquid chromatography mass tandem spectrometry. The compounds were extracted from the matrices with methanol at 40°C within 60 minutes, and then determined by LC-MS/MS using C18 column (100 mm x 2.1 mm x 3.5 µm), the MS/MS detector with negative ESI mode. The calibration curves were linear in the range of 0.1 to 20 μg/mL; the RSD was of 1.74 – 5.01%; and the recovery was in range of 90 – 105%. The method was applied to analyze 20 food samples collected from markets in Hanoi (including dry stevia rebaudiana, stevia powder, stevia tea and soft drinks). The results showed that the composition of steviol glycosides was different from sample to sample. The most abundant steviol glycosides were stevioside and rebaudioside A.