[Screening and confirmation of copper chlorophyll adulteration in olive oils]

To develop a qualitative screening method by high performance liquid chromatograph-photo-diode array (HPLC-PDA) and a confirmation method by ultra performance liquid chromatograph-quadrupole-time of flight mass spectrometry (UPLC-Qtof-MSMS) for Copper Chlorophyll in olive oils.

Commercial liposoluble copper chlorophyll diluted by petroleum ether was purified and concentrated by sep-pak silica solid-phase extraction (SPE) cartridges, the injection was separated by symmetry shield RP18 column, and detected by the PDA at the wavelength 430 nm. The injection was separated by ACQUITY UPLC BEH (18)C and determined by UPLC-Qtof-MSMS in negative atmospheric pressure chemical ionization mode, then confirmed by the exact mass of parent ion and secondary fragment ion provided by the mass spectrum. Samples from supermarket were screened for Cu-pyropheophytin a by established method.

Cu-pyropheophytin a could be used for discrimination as indicative compound whether the olive oils were mixed with copper chlorophyll. 25 samples including olive oil, soybean oil and spirulina from supermarket were screened, Cu-pyropheophytin a was found in one type of olive oil.

This method could be used for screening and qualitative analysis of Copper Chlorophyll in olive oils for its accuracy , reliability and excellent specificity.