PY/GC/MS ANALYSES OF HISTORICAL PAPERS

The thermal degradation of cellulose is an important process in several fields such as the paper industry, biomass combustion, fire retardation, etc. Paper consists mostly of cellulose fibres. Although the fibre source has changed continiously from cotton or linen rags to wood, its nature is still vegetal. Pyrolysis in combination with gas chromatography and mass spectrometry has been used to identify the structures of thermal degradation products with the aim to characterize papers used in different centuries. Pyrolysis of cellulose has also been studied in the presence of the methylating reagent tetramethylammonium hydroxide (TMAH)

The influence of mineral catalysts on racemization of secondary alcohols under pyrolytic temperatures: II part

Pyrolysis of S-1-phenylethanol (PE) with and without catalysts at different temperatures (80-600 degrees C) has been carried out. In the presence of catalysts the partial racemization (<= 25%) and formation of products like styrene, acetophenone and chiral benzylic ethers formation have been detected. Without a catalyst almost no racemization was observed and products formation was not appreciable. The kinetics of racemization has been calculated and the effect of different kind of catalysts has been studied. Pyrolysis of (S)-1-phenylpropanol (PPEs) and (S)-1-phenyl-2,2,2-trifluoroethanol (FEs) have also been carried out at 500 degrees C on zirconium dioxide. The behaviors of catalysts during pyrolysis experiments are studied using SEM technique. A Principal Components Analysis (PCA) model was created using the results obtained with all catalysts at different temperatures and with the main products, i.e., acetophenone, dibenzylic ethers and styrene to discriminate the catalysts on the basis of their effects. Chemical properties of catalysts that are responsible of different effects are deduced. (C) 2011 Elsevier B.V. All rights reserved

Scientific Research Supporting the Study of Pigments and Dyes in Armenian Miniature Painting Art

Illuminated manuscripts can be considered among the most valuable testimonies of the heritage of a culture, either from the artistic or the historical point of view. They are usually produced upon commission in order to disseminate scientific or religious values, or to attest to the wealth of certain rulers. They are also extremely fragile works of art, so that their conservation is an important issue for the museum or library personnel responsible for them. Information about the materials contained in these works \u2013 such as pigments, inks, and supports - is essential for determining a conservation protocol; hence the utility of chemical analysis. Thorough knowledge of such artworks can benefit enormously from the chemical analysis of the materials which comprise the miniatures, the inks and the supports. The analytical techniques available today allow one to obtain very important information using non-invasive or micro-invasive methods. In this study, we will emphasize the possibilities afforded by chemical analysis to enhance our knowledge of the incredibly rich heritage that Armenian manuscripts represent

Micro-Stratigraphical Investigation on Corrosion Layers in Ancient Bronze Artefacts of Urartian Period by Scanning Electron Microscopy, Energy-Dispersive Spectrometry, and Optical Microscopy

The results of the analysis on some fragments of bronze belts and a bowl discovered from southwestern Armenia at the Yegheghnadzor archaeological site are discussed. The samples are dated to the 7–6th millennium BCE from the Urartian period. The artefacts were corroded, and a multilayer structure was formed. To study the stratigraphy of layers and their composition, the samples have been analyzed using SEM-EDS (Scanning Electron Microscopy, Energy-Dispersive Spectrometry) and OM (Optical Microscopy) techniques. The bronze finds appear with the typical incrustations rich in alloy alteration compounds. Concentrations of copper and tin in the alloys were quantified by SEM-EDS: the pattern and the percentage of the alloy are the same for the belts. Regarding the bowl sample, it is constituted by two foils perfectly in contact but different in color, thickness, and composition. The results evidenced that only two elements participate in forming the alloy composition in the samples: Cu and Sn. The tin content is variable from 7.75% to 13.56%. Other elements such as Ag, As, Fe, Ni, P, Pb, Sb, and Zn make up less than 1% and can be considered as impurities

Spectroscopic study of an Armenian manuscript from Biblioteca Universitaria di Bologna

The manuscript of Edessa or ms. 3290, a XVIII century Armenian manuscript kept at Biblioteca Universitaria di Bologna, has been thoroughly studied from the religious, artistic, historical and diagnostic point of view. Non-invasive measurements on the miniatures have been carried out in situ with portable instruments in order to evaluate the pictorial materials used to decorate this beautiful codex, lavishly illuminated with full-page miniatures. The results of the diagnostic study suggested that at least three different painters, each one with its own characteristic palette, contributed to the illumination of the manuscript. Precious colorants were employed for painting, among which of particular interest is the combined use of ultramarine blue and gold, considered the most valuable pictorial materials available to painters. Such a study could be a starting point for a larger research on the heritage of Armenian manuscripts held in Italian institutions

ARMENIAN ILLUMINATED MANUSCRIPTS, A COLOURFUL TESTIMONY OF RELIGIOUS ART EXAMINED BY MOLECULAR SPECTROSCOPY TECHNIQUES

Proceeding in the analysis of the painting materials and techniques of Armenian illuminated manuscripts we refer about a XIV century manuscript with colourful images that were under restoration. Some microsamples were analyzed with microRaman spectroscopy and showed that traditional pigments were used, but some products and mixtures are typical of Armenia illumination, such as vergaut a mixture of indigo and orpiment

A study of some illuminated Armenian manuscripts

Due to its early Christianization, Armenia has preserved a huge patrimony of religious figures in paintings, statues, icons and illuminated codices. Most of the latter are still conserved in Matenadaran Library in Yerevan and their chronology is widely represented from the Middle Ages to XIX century. Armenian manuscripts embrace also various humanities, such as history, philosophy, law, medicine and mathematics. A rich historiographic literature is also present. Therefore it was attractive to carry out an attempt to discover materials and techniques used in the past to prepare the manuscripts and to assemble the codices. Inks and gilding were also considered. Specific materials of Armenian culture will be emphasized. The samples were taken by some of us at the Matenadaran Library of Yerevan (Armenia) and some additional materials, such as Armenian bole and cochineal powder, were found in Yerevan too. The samples were taken with a lancet on deteriorated portions of some papers and parchments pertaining to Armenian codices. Only small fragments were used, since the spectroscopic techniques used need amount down to some micrograms. This is due to their high spatial resolution, enabling also the overlapping layers of pigments and preparation to be studied and their molecular identity to be ascertained in a non-destructive non \u2013invasive way: the same samples could be subjected to other analyses with other techniques. The use of so small samples enabled the use of high performance instrumentation in the Centre of Great Instruments in Modena (CIGS) and to carry out additional experiments with silver nano-particles for Sers technique (surface enhanced Raman spectroscopy). Fourier-Transform infrared (FTIR) spectra were recorded using an Alpha FT-IR spectrometer (Bruker) equipped with the Diffuse Reflection Infrared Fourier Transform ( DRIFT) module in the spectral range 7500 \u2013 375 cm-1 at a resolution of 2 cm-1 cumulating at least 200 scans. The use of SEM-EDX technique was important for characterization of papers and inks. Py/GS/MS was fundamental for organic binding media characterization. The methods of study were the application of atomic (XRF X-ray fluorescence spectroscopy), molecular (FT-IR and microRaman), SEM-EDX and pyrolisis GS/MS spectroscopic techniques to the samples in such a way to obtain the information useful for the understanding of the materials and art techniques applied. Particularly, the analysis of the different inks used in different times and the decoration with gilding on bole with a proper binder was taken into consideration. Experimental Results. Many materials were seen to be used through centuries in Armenian illumination. As already pointed out by Orna and co-workers [1, 2] many materials were identified and the execution techniques were clarified. According to recent investigation [3] other results on new materials and specific products coming from the territory have appeared based on Raman microscopy. A rich polychromy was often present and rare materials are shown to have been employed, such as the green antlerite, a basic copper sulfate mineral present in Caucasus and South of Iran. Lazurite, vermilion, azurite, orpiment, white lead, red lead, indigo, litharge, massicot, carbon were identified. Gilding was applied on an assisa. The Armenian bole is shown to be composed of white Kaolinite and Hematite. Forthcoming information is the application of Raman Sers technique for the identification of the materials and techniques used in Armenian illumination through times. The Armenian Cochineal (from Porphyrophora hamelii Brandt) is composed of carminic acid, that is highly fluorescent in Raman microscopy, unless Sers is used on a sample. With the application of simple atomic and molecular spectroscopy techniques available in many laboratories it was shown to be possible to obtain fundamental information on the specificity of Armenian illumination techniques. The palette of the pigments identified is rich and accompanied by the use of mixtures for preparing green, gray, orange and brown shades; gilding on a red bole with a gold leaf. The most shining red shades were obtained with porphyrophora hamelii, a cochineal proper from Armenia. Literature 1. M. V. Orna, T. F. Mathews, Uncovering the secrets of Medieval Artists, Anal. Chem. 60(1988) 47A-56A. 2. D.E. Cabelli, M.V. Orna, T.F. Mathews, Analysis of Medieval Pigments from Cilician Armenia, Archaeological Chemistry III. Chapt.12 (1984) 243-54. 3. Pietro Baraldi, Gayane Eliazian, Yeghis Keheyan, A study on the polychromy and technique of some Armenian illuminated manuscripts by Raman microscopy, 2nd International Congress of Chemistry for Cultural Heritage, Istanbul, July 9-12, 2012