Development of a liquid chromatography–electrospray ionization tandem mass spectrometry (LC–ESI MS/MS) method for the quantification of bioactive substances present in olive oil mill wastewaters - Bazoti, Fotini N; Gikas, Evangelos; Skaltsounis, Alexios Leandros; Tsarbopoulos, Anthony (Analytica chimica acta, 2006)