Donatella Capitani

NMR and chemometrics in tracing European olive oils: the case study of Ligurian samples.

An NMR and chemometric analytical approach to classify extra virgin olive oils according to their geographical origin was developed within the European TRACE project (FP6-2003-FOOD-2-A, contract number: 0060942). Olive oils (896 samples) of three consecutive harvesting years (2005, 2006, and 2007) coming from Mediterranean areas were analyzed by (1)H NMR spectroscopy. Olive oil samples from Liguria, an Italian region, were chosen as a case study and PLS-DA and SIMCA modeling analyses were used to build up statistical models both to discriminate between Ligurian and non-Ligurian olive oils and to define the Ligurian olive oil class to confirm the declared provenience.

Nuclear Magnetic Resonance to characterize and monitor Cultural Heritage

0079-6565/

Physical-chemical characterisation of acrylic polymers grafted on cellulose

see front matter 2011 Elsevier B.V. A doi:10.1016/j.pnmrs.2011.11.001 Abbreviations: BMA/EA, butyl methacrylate and e Meiboom–Gill; DA, diacids; DEPT, distortionless enh spectroscopy; DTG, Differential Thermal Gravimetry; E HDDA, 1,6 hexanediole diacrylate; HOHAHA, homonu Angle Spinning; HSQC, heteronuclear single quantum Spinning; MG, Monoglyceride; MIP, Mercury Intrusi Imaging; MSD, Mean Squared Displacement; PEG, po liceride; TGA, Thermo Gravimetric Analysis; TMS, tet SEparation; XRD, X-Ray Diffraction Analysis; XRF, X-R ⇑ Corresponding author. Tel.: +39 0690672700; fax E-mail address: donatella.capitani@imc.cnr.it (D. C s u m m a r y

NMR metabolic profiling of organic and aqueous sea bass extracts: Implications in the discrimination of wild and cultured sea bass

An oxidative reaction of cellulose with sodium metaperiodate was performed. The oxidised groups were decomposed by treatment with UV light into free macroradicals. In the presence of acrylic monomers, in the vapour phase, these reactive sites become the starting points for the graft copolymerisation of the cellulose substrate. In this study we examined the graft yield as a function of the polymerisation time and the oxidation degree of cellulose. The grafted polymer was characterised using several analytical techniques, DSC analysis, GPC analysis, viscosity, FTIR and 13C CP-MAS. Information on the morphology of grafted chains with respect to the bulk cellulose was obtained, measuring the dynamic parameters in a careful 13C CP-MAS NMR study. All proposed chemical reactions, if properly conducted, do not affect the crystallinity of cellulose and introduce only a very modest amount of oligomers, therefore they seem suitable for the consolidation and protection of precious cellulose based materials, which are of historical interest.

1H NMR-based protocol for the detection of adulterations of refined olive oil with refined hazelnut oil.

The nuclear magnetic resonance (NMR) technique was used as analytical tool to determine the complete metabolic profiling of sea bass extracts: water-soluble metabolites belonging to different classes such as sugars, amino acids, dipeptides and organic acids as well as metabolites soluble in organic solvent such as lipids, sterols and fatty acids were identified. The metabolite profiling together with a suitable statistical analysis were used to discriminate between wild and cultured sea bass samples. Preliminary results show that discrimination between wild and cultured sea bass was obtained not only using fatty acid composition but also cholesterol and phosphatidylethanolamine and some water-soluble metabolites such as choline, trimethylamine oxide, glutamine, fumaric and malic acids.

Probing the degree of crosslinking of a cellulose based superabsorbing hydrogel through traditional and NMR techniques

A (1)H NMR analytical protocol for the detection of refined hazelnut oils in admixtures with refined olive oils is reported according to ISO format. The main purpose of this research activity is to suggest a novel analytical methodology easily usable by operators with a basic knowledge of NMR spectroscopy. The protocol, developed on 92 oil samples of different origins within the European MEDEO project, is based on (1)H NMR measurements combined with a suitable statistical analysis. It was developed using a 600 MHz instrument and was tested by two independent laboratories on 600 MHz spectrometers, allowing detection down to 10% adulteration of olive oils with refined hazelnut oils. Finally, the potential and limitations of the protocol applied on spectrometers operating at different magnetic fields, that is, at the proton frequencies of 500 and 400 MHz, were investigated.

Noninvasive and nondestructive NMR, Raman and XRF analysis of a Blaeu coloured map from the seventeenth century

The network structure of a cellulose-based superabsorbing material has been probed by using three different techniques: 13C solid state NMR, free swelling in water and uniaxial compression of water swollen samples. A good agreement between the three apporaches has been found in terms of concentration of crosslinks per unit volume. The results have been discussed taking into account that NMR technique is able to detect only chemically effective crosslinks while free swelling and compression are sensitive to elastically effective physical and chemical crosslinks. A depression of swelling capacity and an apparent increase of degree of crosslinking with time, promoted by ageing of the cellulosic material, has been experimentally evidenced and discussed in terms of development of intermolecular physical interactions.

NMR Metabolic Profiling of Transgenic Maize with the Cry1A(b) Gene

A complete multianalytical study of a hand-coloured map from the seventeenth century is presented. The pigments atacamite, massicot, minium, gypsum, carbon black and vermilion were determined by means of XRF and Raman spectroscopy. The state of conservation of the cellulosic support was monitored by means of unilateral NMR. The analysis was nondestructive and noninvasive, and thus several spectra were collected from the same areas, yielding more reliable results without damaging the artwork. The role of copper pigments in the oxidation processes observed in the cellulosic support is discussed, as well as the possible provenance of atacamite as a raw material instead of as a degradation product of malachite.

Analysis of a coloured Dutch map from the eighteenth century: the need for a multi-analytical spectroscopic approach using portable instrumentation.

The metabolic profiles of seeds from the transgenic maize variety 33P67 and of the corresponding traditional variety were investigated using one- and two-dimensional NMR techniques. The transgenic variety carries a functional Cry1A(b) gene, which confers to the plant the ability to produce Bt insect toxin. About 40 water-soluble metabolites in the maize seed extracts were identified, providing a more complete (1)H and (13)C NMR assignment with respect to the assignment reported in the literature. In particular ethanol, lactic acid, citric acid, lysine, arginine, glycine-betaine, raffinose, trehalose, alpha-galactose, and adenine were identified for the first time in the (1)H NMR spectrum of maize seeds extracts. The (1)H spectra of transgenic and nontransgenic seed maize samples turned out to be conservative, showing the same signals and therefore the same metabolites. However, a higher concentration of ethanol, citric acid, glycine-betaine, trehalose, as well as of another compound not yet completely identified, was observed in the transgenic extracts than in nontransgenic samples. So, it was possible to discriminate between transgenic and nontransgenic metabolic profilings through the use of an appropriate statistical analysis.

Monitoring of metabolic profiling and water status of Hayward kiwifruits by nuclear magnetic resonance

A Dutch map from the eighteenth century was multi-analytically analysed making use of energy dispersive X-ray fluorescence (EDXRF), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), Raman and scanning electron microscopy coupled to energy dispersive spectrometry (SEM-EDS). The cellulosic support was characterised and its state of conservation was evaluated. Besides, paramagnetic impurities were detected together with copper metallic chips. The colours present in some areas of the map were also analysed. Vermilion, carbon black and organic pigments were found. Surprisingly, in the green areas, the rare presence of the mineral moolooite (copper oxalate) was detected. A possible biological attack is discussed in order to explain the presence of such compound. Almost all of the techniques used in the analysis were portable, non-destructive and non-invasive, which is very desirable when analysing objects belonging to Cultural Heritage. The need for a multi-analytical approach using portable instrumentation is also discussed.