LC-ESI-MS/MS identification of oleuropein as marker of Olea europaea L., leaves used as a bulking agent in ground oregano and sage

The identification of the secoiridoid oleuropein by LC-ESI-MS/MS (negative) is demonstrated for the quality control directed toward confirmation of the presence of Olea europaea L. leaves used as bulking agent in ground oregano and sage. The described operating conditions are useful for the simple qualitative identification of this marker of O. europaea L. leaves. No tolerance limits are defined for the presence of the above mentioned extraneous vegetable material in ground oregano and sage, the herbs which have been identified in various cases as adulterated with O. europaea L. leaves. Despite the importance of quality control of aromatic herbs, only a limited number of papers have been published on the identification of phenolic compounds as markers of adulteration. The proposed method is simple and suitable for rapid routine analysis.