HPLC DETERMINATION OF STEVIOSIDE IN PLANT-MATERIAL AND FOOD SAMPLES

An HPLC method for the determination of sweet-tasting stevioside (STS) in the leaves of the plant Stevia rebaudiana and in some beverages (e .g. tea, orange juice) was developed. The pre-separation procedure con sisted of extraction of STS from the plant material using boiling wate r and a solid-phase extraction (SPE). Recovery rates of the SPE for th e analysed matrices ranged from 92.8% to 97.8% (for concentrations of STS of 105, 210 and 300 mu g/ml; Relative Standard Deviation (RSD) les s than or equal to 3.3%). The chromatographic separations were realize d using a C-18 column, the mobile phase consisting of methanol and wat er, and with UV detection at 210 nm. The limits of determination of ST S were 5 mu g/ml for the Leaf extracts and the tea sample and 8 mu g/m l for the juice sample.