Analytical chemistry and chemometrics group, Department of Chemistry – University of Rome “La Sapienza”

The recent paper describing the people and the activity of the analytical chemistry and chemometrics group of the University of Genova was meant to inaugurate a series of articles presenting to the readers of NIR News the research groups active in Italy in the field of NIR spectroscopy. In this context, I was asked to contribute with a brief overview of the research lines and the main activities of the group I am currently leading. The research activity of the group focuses on one hand on all aspects of chemometric modelling, for the development of new algorithms to the application of novel and/or existing approaches to various real-world problems; on the other hand, from an experimental standpoint, many efforts are put into the design and build-up of innovative analytical approaches, based on different kinds of spectroscopy (with particular emphasis on the infrared range). Together with this “core” activity, collaborations with other national and international research groups help extending the range of research fields the group is involved in to include, e.g., multi-spectral and hyper-spectral imaging, applications to cultural heritage, biomedical research, forensic science, or sensors, just to cite a few. Such established research collaborations involve the Universities of L’Aquila, of Modena and Reggio Emilia, of Torino, of Milano, of Foggia and of Salerno, the Council for Agricultural Research and Economics (CREA), the National Research Council (CNR) and the Ra.C.I.S. (Italian authority for scientific investigation) in Italy and, among others, the University of Stellenbosch (where I am also Extraordinary Professor), the University College Dublin, the University of Lille, the University of Copenhagen, the University of Silesia, the University of Basque Country and INRAE (Montpellier), at an international level. From an instrumental point of view, as far as NIR is concerned, the group relies on a Nicolet 6700 FT-NIR (Thermo Scientific Inc., Madison, WI) operating in the 4000 and 10,000 cm 1 range, which can acquire signals both in transmission and in reflection, the latter through the use of the equipped integrating sphere. Beside NIR spectral range, the Lab also owns a Perkin Elmer IF320 ultraviolet-visible (UV-Vis) spectrophotometer (PerkinElmer, San Jos e, CA), and a PerkinElmer 1600 Series FT-IR spectrometer (PerkinElmer, San Jos e, CA), which can operate both in transmission and in reflection by means of a ZnSe ATR cell. As anticipated above, the main research lines of the group involve the development of spectroscopy-based analytical approaches and chemometrics, in different fields of application. For sure, food quality and its verification has been for many years one of those fields, with the group contributing to the development of rapid and non-destructive approaches for the characterization of different samples. In particular, recent studies have focused on the possibility of authenticating high value-added products, in most cases with a protected designation of origin, by coupling nearinfrared spectroscopy and chemometric classification strategies. Examples of such product involve walnuts, almonds, hazelnuts, Darjeeling black tea, honey or pasta, just to cite a few. Remaining in the field of food science, the possibility of using advanced chemometrics strategies, such as ANOVA-simultaneous component analysis has allowed to disentangle the effect of the different controlled factors onto the spectroscopic signatures of various processes, such as coffee roasting, milk renneting (collaboration with the University of Milan), chilling damage (collaboration with the University of Foggia), or cheese storage (collaboration with the University of Lille). Moving out of the food sector, by exploiting the concept that in the solid state, if crystallization is regulated by a specific phase diagram, the racemic mixture may have a different spectrum with respect to the individual enantiomers, the possibility of using infrared spectroscopy as a way to experimentally determine the enantiomeric excess of solid-state pharmaceutical formulations has also been investigated.