Besides, several methods for the determination of the target compounds in olive related samples have been published; such as the determination of oleuropein, hydroxytyrosol and tyrosol in olive stems and roots by liquid chromatography [26], the determination of hydroxytyrosol and tyrosol in olive oil by liquid chromatography [27] and [28] or by capillary electrophoresis [29], [30], [31] and [32] and the determination of hydroxytyrosol in olive extracts by micellar liquid chromatography