A rapid high performance liquid chromatographic method for the separation of the alkaloid precursor L-tyrosine and six tetrahydroisoquinoline alkaloids of Papaver somniferum

A high performance liquid chromatographic (HPLC) method was developed for the qualitative and quantitative determination of L-tyrosine and six common tetrahydroisoquinoline alkaloids (papaverine, noscapine, sanguinarine, morphine, codeine and thebaine) of Papaver somniferum. The reversed phase HPLC method yields baseline separation of the alkaloids in 20 min and is achieved using a simple H₂O: MeOH linear gradient. Silanol effects commonly associated with the separation of such strongly basic compounds were minimized by the addition of the amine modifier, triethylamine, to the mobile phase.