Nafion® as advanced immobilisation substrate for the voltammetric analysis of electroactive microparticles: the case of some artistic colouring agents

Voltammetry of microparticles is applied to characterise and to identify solid analytes of interest in the field of cultural heritage. Nafion® is used for the immobilisation of solid microparticles onto the surface of a glassy carbon electrode by exploiting the deposition onto the electrode surface of a micro-volume of a suspension of the microsample in polymeric solution. Cyclic voltammetry and square wave voltammetry are applied to characterise and to identify the microparticles immobilised in the Nafion® coating. The analyte studied in this work is Prussian Blue as a typical inorganic pigment, with a relatively simple electrochemical behaviour. The proposed method is applied to a sample of Venetian marmorino plaster. The performance of Nafion® for this analysis is compared with that of the polymer Paraloid B72

Use of different spectroscopic techniques in the analysis of Roman age wall paintings

In this paper the analysis of samples of Roman age wall paintings coming from: Pordenone, Vicenza and Verona is carried out by using three different techniques: energy dispersive x-rays spectroscopy (EDS), x-rays fluorescence (XRF) and proton induced x-rays emission (PIXE). The features of the three spectroscopic techniques in the analysis of samples of archaeological interest are discussed. The studied pigments were: cinnabar, yellow ochre, green earth, Egyptian blue and carbon blac

Where did Roman masons get their material from? A preliminary DRIFTS/PCA investigation on mortar aggregates from X Regio buildings in the Veneto area (NE Italy) and their potential sources

In this work preliminary results are presented of an on-going investigation aiming to identify the possible material sources employed by ancient Romans in their building activity in the X Regio, the European region corresponding to present north-eastern Italy and Istria (Croatia and Slovenia). The 63 - 420 m fraction of the aggregate component recovered from eleven mortar fragments of buildings located in the Veneto area (in or close to Lio Piccolo, Vicenza and Padua) is studied by diffuse reflection infrared Fourier transform spectroscopy and compared through principal component analysis to samples collected from local potential sources of raw materials. In this regard, the investigated samples from Lio Piccolo present a distinctive complexity, being this site located within the Venice lagoon, an area that has since been undergoing dramatic changes both due to natural and anthropic causes. The Vicenza and Padua sites were considered for comparison sake because they are or were located close to two rivers, the Bacchiglione and the Brenta, that in ancient times flowed into the Venetian lagoon. As expected, from the exploratory investigation reported here, no firm conclusions can be obtained for the mortar samples collected in Lio Piccolo, whereas the likely provenance of the aggregate component of the samples from Vicenza and Padova from the Bacchiglione and the Brenta riverbeds, respectively, is confirmed