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This paper presents the results obtained from the thermal analysis of a set of geomaterials (clays, pyroclastic materials, and industrial recycled materials) to be used as raw materials for the synthesis of geopolymers, specifically designed for the conservation of Cultural Heritage (CH) buildings, particularly in seismic hazard zones such as Sicily. X-ray diffraction and gas volumetric analysis (calcimetry) were applied to this set of raw materials in order to characterize the materials from the chemical and structural point of view. Thermogravimetric analysis (TG), TG coupled to Fourier transform infrared spectroscopy (TG-FTIR), and differential scanning calorimetry were used to characterize their thermal behavior. The statistical treatment of the thermogravimetric data by principal component analysis and hierarchical clustering analysis highlights the direct relation between the thermal data and the material composition that will be exploited for the selection of the best materials to obtain geopolymers specifically designed for the conservation of CH buildings.

The aim of the current work is twofold: to demonstrate the application of in situ non-invasive imaging by portable atomic force microscopy (AFM) on the surfaces of a violin and to integrate compositional and mechanical analysis at the nano scale level on model samples of varnished wood. These samples were prepared according to traditional recipes by an Italian lute-maker family well practised in the art. Samples of oil and spirit-based varnishes on maple wood, naturally and accelerated light aged, were studied. AFM was used to measure the nanomechanical properties of the model samples and established that the spirit-based varnish was stiffer than the oil-based. Synchrotron radiation micro- Fourier Transform Infra-red analysis of the layer structure revealed that stiffer spirit-based varnish showed less penetration into the wood than the oil-based. Further PeakForce Quantitative Nanomechanical Mapping (QNM) demonstrated a difference in adhesion values between the oil- and spirit-based samples.

Although many prominent artists have experimented with pastels, this technique has been the subject of very limited scientific research. The first known recipes of pastels date back to the 16th century, but only during the 18th century did the pastel technique become more common. Identifying and characterising the organic constituents in pastels materials is challenging given that they are present in extremely low concentrations and could be produced using many organic substances, whose chemical composition alters during ageing. The chemical-physical behaviour of organic media in artworks is often crucial in causing the degradation problems, which need to be addressed by conservation. We evaluated the applicability of an analytical approach based on chromatography and mass spectrometry to investigate the composition of the pastels used by Umberto Boccioni in a drawing dated 1908 and conserved at the Museo del Novecento in Milan (Italy). The investigation of the formulation of artists’ pastels used in the first decade of the 20th century is particularly important in order to improve the knowledge of this technique. The analysis highlighted the presence of proteins and plant gums in the artwork samples, with differences in the composition for the different samples.

Green pigments in micro-samples taken from three late-medieval painted objects from Norwegian churches have been investigated with the aim to characterize their constituents and understand how they relate to damages observed in passages containing green paints. The cross-sections were analyzed by optical microscopy under visible and UV light, Scanning Electron Microscopy coupled with Energy Dispersive X-Ray Spectrometry and vibrational spectroscopies (Raman, ATR-FTIR). In addition, Gas Chromatography coupled with Mass Spectrometry was employed for the characterization of binding media, using a derivatization methodology recently developed for the detection of metal soaps in paint samples. This extensive characterization aided the identification of the individual constituents and the stratigraphy of green paints. It also builds the foundation for future ageing studies that can provide better insights into the mechanisms of the processes at stake in selective delamination of paints containing copper complexes.

We investigated the cedar wood doors of the Bahia Palace in Marrakesh (Morocco), which are richly decorated with geometric motifs. A gas chromatographic mass spectrometric analytical procedure (GC/MS) was used to characterize the organic binders in micro samples collected from one of the doors. In order to examine the artist's palette, X-ray fluorescence (XRF), Raman and Fourier transform infrared spectroscopy (FTIR) and high performance liquid chromatography (HPLC-DAD), were applied to samples in fragments or on cross-sections of the embedded samples. This multi analytical approach effectively identified the polychrome decoration technique, mainly based on the use of animal glue as a proteinaceous binder, and characterized the superficial varnishes. Lastly many of the different pigments used for the creation of these works of art were identified. We believe that this study contributes significantly to the knowledge of Moroccan art from a material and technological point of view.

In this paper we present a new analytical GC/MS method for the analysis of mixtures of free fatty acids and metal soaps in paint samples. This approach is based on the use of two different silylating agents: N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and 1,1,1,3,3,3-hexamethyldisilazane (HMDS). Our experimentation demonstrated that HMDS does not silylate fatty acid carboxylates, so it can be used for the selective derivatization and GC/MS quantitative analysis of free fatty acids. On the other hand BSTFA is able to silylate both free fatty acids and fatty acids carboxylates. The reaction conditions for the derivatization of carboxylates with BSTFA were thus optimized with a full factorial 32 experimental design using lead stearate and lead palmitate as model systems. The analytical method was validated following the ICH guidelines. The method allows the qualitative and quantitative analysis of fatty acid carboxylates of sodium, calcium, magnesium, aluminium, manganese, cobalt, copper, zinc, cadmium, and lead and of lead azelate. In order to exploit the performances of the new analytical method, samples collected from two reference paint layers, from a gilded 16th century marble sculpture, and from a paint tube belonging to the atelier of Edvard Munch, used in the last period of his life (1916–1944), were characterized.

In this paper we present the technical study of protein-drying oil mixtures in the paint formulation of original manufacturers paint tubes from Fabbrica di colori per Belle Arti Maimeri dating back to the 1950s. The study is part of a wider research project aimed at understanding the chemistry of protein-drying oil mixtures, and how the oil curing in the presence of proteins may affects the protein analysis with mass spectrometric based techniques. Tempera grassa, according to traditional Late Medieval and Renaissance painting techniques, entails the use, as paint binder, of a mixture of a drying oil with a water miscible medium, commonly egg. The paints analysed in this study were, according to technical documentation available at the manufacturer, based on a mixture of linseed oil, ovalbumin and mastic resin. All the components of the paints were detected but proteins proved very challenging. They could not be detected by pyrolysis coupled to gas chromatography-mass spectrometry, nor by using classical procedures for gas chromatography – mass spectrometry analysis of amino acids after hydrolysis. A new analytical procedure based on two subsequent hydrolysis steps assisted by microwaves was implemented and proved to be successful. The first step with trifluoroacetic acid was aimed at a partial hydrolysis of proteins into peptides, for their efficient extraction. The second with hydrochloric acid in the vapour phase was used for a complete hydrolysis of peptides into amino acids for the GC–MS analysis. Linking experimental results on the tempera grassa paints to data obtained on the curing of oil/protein mixtures in paint mock-ups, the hypothesis that copolymerisation of proteins and the oil has taken place is proposed, and a discussion on how this may affect protein detection is carried out.

The influence of free metal stearates, other metal soaps and free fatty acids on the water sensitivity of modern oil paint swatches from three brands of artists’ manufactured tube paints was investigated. The swatches produced in 2006 and tested for water sensitivity in 2008 were re-tested, and changes in sensitivity were recorded. Swatches with a range of sensitivity to water and those that exhibited visible surface deterioration were selected for chemical and optical characterisation. This included a novel method of sample preparation for gas chromatography coupled with mass spectrometry (GC/MS) for quantitative analysis of free fatty and dicarboxylic acids and related metal soaps. Results suggested that the proportion of free fatty acids and metal soaps in the swatches does not relate to water sensitivity of the paint surface. It is therefore likely that the polymeric/ionomeric network plays an important role in water sensitivity. Results showed that fatty acid efflorescence is linked with high levels of free fatty acids (FFA) in the paint swatch and that the extent of the efflorescence is proportional to the quantitative results for free fatty acids found in the GC/MS analyses.

Since the introduction of the term ‘geopolymer’ by Davidovits in 1978, many works have been published, sometimes providing clear and concise indications, and other times creating confusion about what are a geopolymer. What seems interesting beyond the terminology discourse is the advantage of low CO2 emissions, the use of waste industrial byproducts in their implementation and the resistance to air pollution and aggressive agents. Playing on the combination of the different precursors and alkaline activators, geopolymers can reach competitive mechanical properties and significant environmental benefits. The materials, with specially designed formulations, can be fireproof, breathable, resistant to rising salts and acid rain, as well as products with low emission of carbon dioxide. Furthermore, a further advantage is the ability to imitate natural, artificial and stone materials. There are hundreds of papers about characteristics, properties both of precursors and final product, but only a few of them about the Cultural Heritage Application. Despite this, the data shown by the few publications present to date give hope for a use of these materials for the consolidation, conservation and restoration of the heritage built within the historical centres, where the low CO2 emissions and the characteristics shown by the geopolymers could bring a huge benefit to the environment and the protection of the structures themselves. In this work, we briefly review the bibliography available on the applications of these materials to Cultural Heritage, hypothesising future uses aimed at specific urban contexts, where the application could play a key role in the future projects to restore the built heritage.

International audience; The huge number of complex formulations of synthetic dyes and pigments commercialized in the 19th century makes their comprehensive characterization both difficult and fundamental for their successful identifications in artworks. The description of the exact starting composition of a wide collection of reference materials is preliminary to the study of the challenging photo-degradation processes in which most of the early synthetic dyes and pigments are involved. In this paper, four eosin-based lakes, all containing eosin Y, and one also containing eosin B, but differing in the organic and inorganic materials used as fillers, were fully characterized. These formulations were reconstructed on the base of historical recipes from the extensive Wiesel's collection, dated to the 19th century and bought by Dr Kremer (Kremer Pigmente, Germany) in the 1990s. The composition of each formulation was characterized by Fourier transform infrared spectroscopy (FT-IR) and luminescence spectroscopy was used as a probe for their inert-distinction. Reference paint layers were then prepared by casting the lakes in linseed oil, and their ageing and impact on color change was monitored for one year by analyzing two sets of paint model systems by colorimetry. For each system, two sets were prepared and one was stored in the dark while the other exposed to natural light. The material distribution and homogeneity of the samples were tested by Synchrotron Radiation based micro infrared spectroscopy (SR-μ-FT-IR). Finally, an ultra-sensitive method based on Liquid Chromatography coupled with High Resolution Mass Spectrometry (LC-HRMS) allowed us to characterize eosin degradation products detected but never identified before, and to evaluate their kinetics of formation.

In this work, an innovative sampling and preconcentration method followed by analysis with liquid chromatography coupled to tandem mass spectrometry with electrospray ionization (LC-ESI-MS/MS) was developed for the determination of different emerging pollutants (five anti-inflammatory drugs and one antibacterial agent) in water matrices. Thin-film microextraction blades, consisting of stainless steel blades with a coating made of divinylbenzene, have been employed. The blades, fixed onto a stainless steel support, were mounted on a laboratory stirrer with adjustable speed, immersed in water samples and eluted with methanol. The analytical procedure was developed, carefully optimizing stirring speed and extraction time. A good reproducibility among the blades was observed; quantitation limits at the ng L-1 level were achieved. Calibration curves were constructed by applying the whole procedure to tap water samples, free from analytes, spiked with standards in the concentration range 0.01-2 μg L-1 ; good linearity was obtained, with R2 between 0.9984 and 0.9991. The optimized method was applied to tap and surface waters; two anti-inflammatory drugs were detected at the ng L-1 level in surface water. In one sample, diclofenac and naproxen were measured at 26 ± 5 and 15 ± 1 ng L-1 , respectively; only diclofenac was quantified in the other sample at 14 ± 3 ng L-1 .

This work proposes a multi-analytical approach to determine the additives in historical mortars, the use of which is widely described in bibliographical sources, but has rarely been reported in the literature. A protocol to thoroughly analyse mortars was created (optical microscopy, X-ray diffraction, infrared spectroscopy, thermal analyses and gas chromatography – mass spectrometry). These techniques had already been carried out on samples from various sites from the Roman to the modern era, finding that additives had only been used in the mortars from the internal masonry at our sampling site: the medieval military shipyard of Amalfi (Italy). The investigations yielded information on the production technology, and FT–IR and GC–MS revealed a saccharide material-based additive in the mortars, of plant origin. The FT–IR spectra suggested the presence of a natural gum, which has been used since ancient times to strengthen the cohesion properties of mortars and their resistance to tensile stress

For more than a century, the analyses of painting fragments have been carried out mainly through the preparation of thick resin-embedded cross-sections. Taking into account the development of innovative micro-analytical imaging techniques, alternatives to this standard preparation method are considered. Consequently, dedicated efforts are required to develop preparation protocols limiting the risks of chemical interferences (solubilisation, reduction/oxidation or other reactions) which modify the sample during its preparation, as well as the risks of analytical interferences (overlap of detected signals coming from the sample and from materials used in the preparation). This study focuses particularly on the preparation of thin-sections (1–20 μm) for single or combined fourier transform infrared (FTIR) spectroscopy and X-ray 2D micro-analysis. A few strategies specially developed for the μFTIR analysis of painting cross-sections have already been reported and their potential extrapolation to the preparation of thin-sections is discussed. In addition, we propose two new specific methods: (i) the first is based on a free-embedding approach, ensuring a complete chemical and analytical neutrality. It is illustrated through application on polymeric design objects corpus; (ii) the second is based on a barrier coating approach which strengthens the sample and avoids the penetration of the resin into the sample. The barrier coating investigated is a silver chloride salt, an infrared transparent material, which remains malleable and soft after pellet compression, enabling microtoming. This last method was successfully applied to the preparation of a fragment from a gilded Chinese sculpture (15th C.) and was used to unravel a unique complex stratigraphy when combining μFTIR and μXRF.

In the Comment by Dr. I. Rabin from Bundesanstalt fur Materialforschung und -prufung in Berlin are stated many conjectures and apparent guesses contradicting several of our interpretations. Most of Rabin's ‘guesses’ and interpretations are unwarranted. Below we rebut some of the misinterpretations under separate headings.

A chemical investigation of the organic paint binders of the Giant Buddhas of Bāmiyān was performed using an analytical approach based on mass spectrometry, combining traditional gas chromatography/mass spectrometry protocols with advanced proteomics methodologies. The research was carried out on a selection of rescued fragments. The data revealed the use of egg proteins as the paint binders of the original layers, in accordance with the traditional use of this proteinaceous medium in antiquity, spanning from the Mediterranean basin to the Far East, and already in the Bronze Age. Egg tempera was thus known to artists of the region in the first centuries AD, probably also due to the position of the Bāmiyān valley, which was connected to the Silk Road. Milk was found in the first historical overpaintings. A new proteomics approach was used, which was able to identify the source of the milk proteins present in the restoration layers, despite their age and degradation. In particular cow's and goat's milk were both found, in agreement with the documented presence of rich pastures in the Bāmiyān valley when the historical restorations were carried out. Investigating the materials of the Giant Buddhas not only enabled us to obtain isolated data on these invaluable works of art, which are now lost, but contributes to understanding the big ªpuzzleº of our past and the development of our culture, by implementing and supporting written sources, stylistic and anthropological studies with molecular data.

Eosin is a xanthenic synthetic organic dye/pigment synthesized by Caro in 1873. It was precipitated with lead and aluminum salts and commercialized as geranium lake and it was one of the most brilliant hues in the palette of the Impressionist painter Vincent van Gogh. Unfortunately, the high photosensitivity of eosin has caused the evident fading of the intense pink colorations of his canvas paintings into lighter ones. This work aims at underlying the contribution of several complementary different analytical techniques in disclosing a very complex and still little-known topic such as the degradation process of eosin.

Journal of cultural heritage - In Press.Proof corrected by the author Available online since lundi 18 mars 2013

This paper describes a method for reliably identifying saccharide materials in paintings. Since the 3(rd) millennium B.C., polysaccharide materials such as plant gums, sugar, flour, and honey were used as binding media and sizing agents in paintings, illuminated manuscripts, and polychrome objects. Although it has been reported that plant gums have a stable composition, their identification in paint samples is often doubtful and rarely discussed. Our research was carried out independently at two different laboratories: the Getty Conservation Institute in Los Angeles, USA (GCI) and the Department of Chemistry and Industrial Chemistry of the University of Pisa, Italy (DCCI). It was shown in a previous stage of this research that the two methods give highly comparable data when analysing both reference paint samples and paint layers from art objects, thus the combined data was used to build a large database. In this study, the simultaneous presence of proteinaceous binders and pigments in fresh and artificially aged paint replicas was investigated, and it highlighted how these can affect the sugar profile of arabic, tragacanth, and fruit tree gums. The environmental contamination due to sugars from various plant tissues is also discussed. The results allowed the development of a new model for the reliable identification of saccharide binders in paintings based on the evaluation of markers that are stable to ageing and unaffected by pigments. This new model was applied to the sugar profiles obtained from the analysis of a large number of samples from murals, easel paintings, manuscripts, and polychrome objects from different geographical areas and dating from the 13(th) century BC to the 20(th) century AD, thus demonstrating its reliability.