Simple isocratic RP-UHPLC-MS methods for the determination of steviols and its glycosides: Quality control perspectives

Stevia is well-known for its unique non-caloric intense sweetness and recognising as one of the most acceptable sweeteners. Therefore, quality control and metabolite profiling perspectives, two isocratic reverse-phase UPLC-PDA-ELSD-MS methods were developed to determine nine diterpene glycosides (method A) and isomeric compounds (steviol and isosteviol; method B). Both the methods were validated and found as per the ICH guidelines for accuracy (recovery), precision (Intraday, interday, and intermediate precision), linearity, and regression coefficient (r2), ruggedness (eluent concentration ± 2 mM, column oven temperature ± 3 °C and retention time), and system suitability (theoretical plate count, asymmetric factor, injection precision and resolution). LOD for steviol and its glycosides were found between 0.92 and 5.22 μg/mL while LOQ were 2.78–18.29 μg/mL, respectively. Validated methods had shown only the presence of steviol glycosides in Stevia rebaudina samples while LC-ESI-MS/MS revealed the identification of 46 different class of molecules. These methods will be helpful to monitor quality in Stevia production and its derived products.