Paper spray mass spectrometry profiling of olive oil unsaponifiable fraction for commercial categories classification.

A new method for a fast molecular profiling of olive oil unsaponifiable fraction has been developed. This approach, based on paper spray mass spectrometry, allows obtaining MS data with only a few minutes of analysis and without significant solvent and disposable consumption. Tandem mass spectrometry and high-resolution mass spectrometry experiments have been performed to identify the main ions detected. The MS data coming from the analyses of sixty-three samples of three different olive oil categories: extra virgin olive oil (EVOO), virgin olive oil (VOO), and pomace olive oil (POO), have been used to test the discriminative potential. Both unsupervised (PCA and HCA) and supervised (kNN and LDA) chemometric procedures have been applied with good results in prediction. The same approach was tested using direct infusion mass spectrometry data to confirm the ability of paper spray fingerprinting to classify different olive oils correctly.