Determination of higenamine in dietary supplements by UHPLC/MS/MS method
From 1st January 2017 higenamine was added on the WADA (World Anti-doping Agency) Prohibited list under S3 group beta-2 agonists as at all times banned substance for the athletes. The main origine of higenamine (or norcoclaurine) are different plants including Nandina domestica, Aconitum carmichaelii, Asarum heterotropioides, Galium divaricatum, Annona squamosa, Nelumbo nucifera etc. Higenamine main use is related to weight loss and it could be found (un)labeled in different dietary supplements. The objective of this study was development of sensitive and reliable UHPLC/MS/MS method for determination of higenamine in various dietary supplement samples. In order to obtain high method sensitivity, hydrophilic interaction liquid chromatography (HILIC) mode was applied. Separation was carried out on UHPLC Acquity BEH HILIC analytical column (2.1 mm × 100 mm, 1.7 μm particle size). Mobile phase consisted of 0.1% formic acid in water and acetonitrile, respectively, was mixed in ratio of 30:70, v/v. Flow rate was set at 0.2 mL min−1. Quercetin was used as an internal standard. ESI (+) source ionization mode using multi reaction monitoring (MRM) mode was utilized and three ion transitions of higenamine were followed 272.08 → 107.01, 272.08 → 161.07 and 272.08 → 77.08. Developed method was fully validated and applied for identification and quantification of higenamine in different dietary supplements. According to the results, the most of investigated supplements were free of higenamine, and on the other hand, presence of higenamine was confirmed in some samples while it was not declared on the label.