Development and application of a quantitative method based on LC–QqQ MS/MS for determination of steviol glycosides in Stevia leaves

Stevia is a currently well-known plant thanks to the presence of steviol glycosides, which are considered as sweeteners obtained from a natural source. In this research, a method based on LC–MS/MS by using a triple quadrupole detector was developed for quantitation of 8 steviol glycosides in extracts from Stevia leaves. The ionization and fragmentation parameters for selected reaction monitoring were optimized. Detection and quantitation limits ranging from 0.1 to 0.5ng/mL and from 0.5 to 1ng/mL, respectively, were achieved: the lowest attained so far. The steviol glycosides were quantified in extracts from leaves of seven varieties of Stevia cultivated in laboratory, greenhouse and field. Plants cultivated in field presented higher concentration of steviol glycosides than those cultivated in greenhouse. Thus, the way of cultivation clearly influences the concentration of these compounds. The inclusion of branches together with leaves as raw material was also evaluated, showing that this inclusion modifies, either positively or negatively, the concentration of steviol glycosides. [Display omitted] •A method for absolute quantitation of steviol glycosides is proposed.•The compounds are quantified in extracts from Stevia leaves.•The influence of cultivation conditions on Stevia is evaluated.•The use of branches+leaves as raw material is also evaluated.