INNOVATIVE MULTIDIMENSIONAL CHROMATOGRAPHIC APPROACHES FOR THE ISOLATION, IDENTIFICATION AND GENUINENESS ASSESSMENT OF FOOD CONSTITUENTS

The first part of the Ph.D. course was devoted to the development and validation of a fast gas chromatographic (GC) method for the analysis of pesticides in food samples. Two reduced-scale quick, easy, cheap, effective, rugged, and safe (QuEChERS) procedures, combined with fast gas chromatography-triple quadrupole mass spectrometry (GC-QqQ MS), were developed and then validated for the determination of 35 pesticides in different vegetable products. Another project concerned the development of an MDGC-MS/IRMS prototype. Isotope Ratio Mass Spectrometry (IRMS) is commonly recognized to be able to provide information about the geographical, chemical, and biological origins of substances. Even if GC-C-IRMS can provide isotopic analysis of complex mixtures, the reduced chromatographic performance could generates coeluted GC peaks leading to an unreliable isotopic ratio measurement. To overcome this issue, an MDGC-MS/IRMS prototype was developed during the three years, characterized by an improved resolution capability thanks to the heart-cut approach and simultaneous qMS and IRMS detection. Based on the isotopic ratio of a target compound, an application was developed dealing with the investigation of several natural italian white truffles together with the genuineness evaluation of commercial products flavoured with truffles. Another project concerned the isolation and characterization of high amounts of pure molecules, by means of a multidimensional prep-GC instrument. Conventional preparative GC systems present different limitations when highly pure compounds have to be collected at milligrams level. With the intention to improve the productivity of the preparative approach, a tridimensional GC system has been successfully developed, exploiting wide-bore columns operated in heart-cut mode, allowing the collection of high amounts of highly pure components in a reasonable working time.