Utilisation of a Simple and Fast HPLC-UV Method for Separation and Quantification of Ephedrine Alkaloids in Herb of Different Ephedra Species
Ephedra is a plant with a long history of medicinal use, the main indications being asthma, rhinitis and bronchospasm. However, nowadays it is often misused/abused for weight-loss, performance enhancing and doping. The pharamcological effects are ascribed to the ephedrine alkaloids present in the plant. The aim of the study was to quantify Norephedrine (NE), Ephedrine (E), Pseudoephedrine (PE) and Methylephedrine (ME) in herb extracts of nine different Ephedra species using high performance liquid chromatography with UV detection (HPLC-UV). The alkaloids were separated on the column Symmetry C18 (5 µm, 3.9 x 150 mm). The mobile phase was delivered at the flow rate of 1 ml/min. The mobile phase was prepared with 390 ml of acetonitrile, 610 ml of pure water, 0.8 ml of o-phosphoric acid and 4.8 g of sodium lauryl sulfate. The UV detector operated at 208 nm. We found that the utilized HPLC-UV method for separation and quantification of ephedrine alkaloids was very selective, sensitive and simple. The total content of NE, E, PE and ME ranged from 0.4 mg/g dry weight (Ephedra foeminea, from Austria) to 71.9 mg/g dry weight (Ephedra major, from Morocco). None of the investigated alkaloids were detected in Ephedra altissima.