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The use of natural dyes in several areas is regulated by current European and non-European legislation, due to various problems with synthetic dyes. The analysis revealed that the lichen studied: Xanthoria parietina has potential natural dye sources and provides bright colors for extraction solvents. Furthermore, dyed wool and toile fabric have good fastness properties in ammonia fermentation and boiling water, both with and without mordants. The sample dyes with Xanthoria parietina were characterized by several analytical techniques: high-performance liquid chromatography with diode array detection (HPLC-DAD) and electrospray ionization with tandem mass spectrometry (HPLC-ESI-Q-ToF). As compounds from Xanthoria parietina form a complex with mordants and tissues, it is impossible to identify the molecules responsible for coloring using chromatographic techniques. However, we have evaluated the dyeing power of their major molecule, parietin. To further confirm the coloring power of the isolated parietin molecule, we performed a dye test with pure parietin. Thus, CIALAB analyses have shown parietin is the molecule responsible for the coloring obtained by Xanthoria parietina. The utilization of parietin derived from lichens facilitates the development of sustainable dyes for textile coloring, presenting an environmentally friendly alternative to synthetic dyes while simultaneously enriching lichen biodiversity.

This article reviews the research recently undertaken to characterise and identify early synthetic dyes (ESDs) and synthetic organic pigments (SOPs) as well as study their degradation pathways with a focus on cultural heritage applications. Since the invention of the first fully synthetic dye in 1856, these materials have been used in a variety of historic objects and artworks, such as textiles, furniture, prints, paintings, drawings, etc. The synthesis of new dyes and their implementation into pigment formulations were rapid phenomena, so that by the beginning of the 20th century, thousands of new molecules were patented and commercialised. This review will focus on these early formulations synthesised up to approximately 1914 and the outbreak of World War I. ESDs and SOPs represent a challenge from an analytical point of view. Molecular databases are fundamental for the unequivocal identification of these compounds, but reference materials are not always readily available. A combination of analytical techniques is often needed for characterisation, especially in the case of SOPs, which have both organic and inorganic components. Furthermore, the degradation of these molecules can jeopardise their detection in historic objects that have been exposed to light, humidity and temperature fluctuations. Nevertheless, ESDs and SOPs are important research tools. As the dates of their first synthesis are often known with precision, based on patent information, their detection can be used to refine the production date of objects. Additionally, their trade from Europe to the world and their adoption in artistic practices around the globe is an active area of research.

Acrylonitrile butadiene styrene (ABS) is a thermoplastic polymer widely used in several everyday life applications; moreover, it is also one of the most employed plastics in contemporary artworks and design objects. In this study, the chemical and thermal properties of an ABS-based polymer and its photo-degradation process were investigated through a multi-analytical approach based on thermal, mass spectrometric and spectroscopic techniques. LEGO(& REG;) building blocks were selected for studying the ABS properties. First, the composition of unaged LEGO(& REG;) bricks was determined in terms of polymer composition and thermal stability; then, the bricks were subjected to UV-Vis photo-oxidative-accelerated ageing for evaluation of possible degradation processes. The modifications of the chemical and thermal properties were monitored in time by a multi-technique approach aimed at improving the current knowledge of ABS photodegradation, employing pyrolysis online with gas chromatography and evolved gas analysis, coupled with mass spectrometric detection (Py-GC-MS and EGA-MS), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and corroborated by external reflection FT-IR spectroscopy. The multimodal approach provided new evidence on the two-step degradation pathway proposed for ABS, defining molecular markers for polybutadiene oxidation and styrene-acrylonitrile depolymerization. Moreover, the results highlighted the feasibility of correlating accurate compositional and thermal data acquired by bulk techniques with external reflection FT-IR spectroscopy as a non-invasive portable tool to monitor the state of conservation of plastic museum objects in-situ.

Determining the dye source used in ancient coloured textiles is challenging, especially if little information is available on the raw materials or traditional recipes of the geographical area. This is the case of South American dye sources and particularly of yellow ones, the widest and highest photo-sensitive class. In this work, Cosmos sulphureus, an annual plant whose flowers were used for dyeing in nuances of red to yellow, was analysed. The petal content was analysed by high-pressure liquid chromatography with a diode array detector (HPLC-DAD) and high-resolution mass spectrometer (HPLC-HRMS) and sixteen compounds were identified, some of which had never been reported in Cosmos sulphureus. Not mordanted and mordanted yarns, dyed with Cosmos sulphureus petal extract and artificially aged, were analysed to assess the role played by the mordant and ageing. The information pointed at Cosmos sulphureus as the dye source in a yellow Chimú / Chancay textile (1000-1047 AD).

Home Analytical Chemistry for the Study of Paintings and the Detection of Forgeries Chapter Analysis of Natural and Synthetic Organic Lakes and Pigments by Chromatographic and Mass Spectrometric Techniques Francesca Sabatini & Ilaria Degano Chapter First Online: 09 September 2022 390 Accesses Part of the Cultural Heritage Science book series (CUHESC) Abstract This chapter aims to provide an overview of natural and synthetic organic lakes and pigments and of how their analysis by chromatography and mass spectrometry can provide useful information in the examination of works of art. The characteristics of natural organic colourants are reviewed, including information on their provenance and uses in the production of lakes; information on the date of production, availability as paint products and application in artworks of the most important synthetic organic pigments is also provided. This chapter specifically illustrates the state-of-the-art of organic pigments analysis by high performance liquid chromatography with different detectors, and by gas chromatography – mass spectrometry also coupled to analytical pyrolysis. Different mass spectrometry based techniques used both as detector and directly applied on a sample or its extract are also presented. Particular attention is paid to sample preparation; further issues related to difficulties in finding relevant standards or reference materials and understanding photo-degradation processes occurring in degraded organic pigments are also discussed. Several case studies are presented, showing the potentialities of liquid chromatography interfaced with mass spectrometry in determining properties of the samples which can be of assistance for assessing the provenance, dating or even the authenticity of a painting.

Recently, a notable change has occurred in how street art murals are perceived by art history and the general public, with a growing recognition of their social and cultural significance and a new focus on preserving the most representative modern urban murals for future generations. An interesting case study is constituted by the "UBUNTU" mural (Ivan Pontevia and Daniele Castagnetti, Reggio Emilia, 2018), whose appearance has radically changed in a few years. Indeed, the intense and direct exposure to sunlight as well as the environmental and polluting agents have induced the bleaching and fading of the original highly fluorescent hues. To investigate the degradation processes that are occurring, five micro-samples were collected from different fluorescent-coloured areas and analysed by a combined approach based on & mu;-Raman and Surface Enhanced Raman Spectroscopy (SERS), High Performance Liquid Chromatography coupled with Diode Array Detector and mass spectrometry (HPLC-DAD and HPLC-MS), and Pyrolysis Gas Chromatography coupled with Mass Spectrometry (Py-GC-MS). The analytical protocol applied allowed us to disclose the painting materials used by the artist and fully characterise the ageing phenomena occurring in the mural that are possibly responsible for its colour ephemerality.

Familial hypercholesterolemia (FH) is an autosomal dominant disease that has a prevalence of approximately 1/250 inhabitants and is the most frequent cause of early coronary heart disease (CHD). We included 1.343.973 women and 1.210.671 men with at least one LDL-c measurement from the Catalan primary care database. We identified 14.699 subjects with Familial hypercholesterolemia-Phenotype (FH-P) based on LDL-c cut-off points by age (7.033 and 919 women, and 5.088 and 1659 men in primary and secondary prevention, respectively). Lipid lower therapy (LLT), medication possession ratio (MPR) as an indicator of adherence, and number of patients that reached their goal on lipid levels were compared by sex. In primary and secondary prevention, 69% and 54% of women (P = 0.001) and 64% and 51% of men (P = 0.001) were on low-to-moderate-potency LLT. Adherence to LLT was reduced in women older than 55 years, especially in secondary prevention (P = 0.03), where the percentage of women and men with LDL-c > 1.81 mmol/L were 99.9% and 98.9%, respectively (P = 0.001). Women with FH-P are less often treated with high-intensity LLT, less adherent to LLT, and have a lower probability of meeting their LDL-c goals than men, especially in secondary prevention.© 2023. The Author(s).

Street art murals are an artistic expression strictly interwoven in the urban landscape, and in recent years have received increasing attention as cultural heritage at risk. Today there is intense debate regarding the value assessment and choices related to the conservation of urban art; however, the evaluation of the stability of modern paint materials in outdoor environment is preliminary to any possible preservation strategy. In particular, the identification of the materials constituting a street artwork is critical for the preservation of these non-permanent heritage elements and to define the best restoration approaches. In this work, we performed a set of analyses of microsamples based on spectroscopy, analytical pyrolysis, gas and liquid chromatography, and mass spectrometry to identify paint materials (binders, pigments, additives, degradation products and conservation/restoration materials) of a selection of mural paintings, covering 60 years of history (1953–2014). The goal of this work was to identify the materials used to produce different mural paintings and to relate and compare their different compositions with previous studies in order to describe the evolution of the materials during the last 60 years. The collected knowledge and the limited data available in literature were exploited to increase the scientific background on the materials used by street artists, and to fill the lack of knowledge on this emerging topic.

Among the artists’ materials of the nineteenth century, pastel crayons merit scientific interest since their early commercial formulations are mostly unknown and, until now, have been considerably less studied with respect to other contemporary painting materials. In this framework, research herein reports the results of a comprehensive multi-analytical study of 44 pastel crayons of two recognized brands (LeFranc and Dr. F. Schoenfeld) from the Munch museum collection of original materials belonging to Edvard Munch. The integrated use of complementary spectroscopic and hyphenated mass-spectrometry techniques allowed the compositional profiles of the crayons to be traced providing the identification of the inorganic and organic pigments, the fillers/extenders and the binders. All crayons resulted to be oil- based and the binder was identified to be a mixture of a drying oil (safflower or linseed oil), palm oil or Japan wax and beeswax. Among others, pigments such as ultramarine, chrome yellows, Prussian blue, manganese violet, viridian and madder lake have been identified. A significant alignment in formulations of the brands was observed with the only exception of the greens which showed distinctive pigment and filler compositions. The analytical information provided for these commercial artists’ materials will be of great interest for academia, museum and other institutions hosting art collections dating from the same period and it will be used by the Munch museum to draw proper conservation strategies of its own artwork collections.

Diamond Green G (CI 42040, Basic Green 1) is a triarylmethane dye mostly employed in the industrial dyeing of miscellaneous natural and artificial textile fibres, in the production of printing inks and as an anti-fungal agent for aquaculture products. Diamond Green (DG) tends to fade under light irradiation, similar to several other dyes and pigments belonging to the triarylmethane family. In this paper, an in-solution degradation study was carried out to shed light on DG photostability. The experiments were performed by artificially irradiating DG in water and dimethyl sulphoxide, and analysing aliquots sampled at different time intervals by ultra-high performance liquid chromatography coupled with diode array detector quadrupole and time of flight tandem mass spectrometry. The degradation products formed were characterised and the product-ion spectra discussed and interpreted. On the basis of the structure of the identified compounds and their kinetic trend in relation to the accelerated ageing time, degradation mechanisms were proposed for DG, taking into account the role played by the solvent. Finally, the dyeing formulation of an historical textile sample, collected from a stage costume worn in a Zeffirelli lyric opera, was determined utilising the information collected from the analysis of irradiated DG solutions.

Fibres and dyes in four Coptic textiles preserved at the Moghadam Museum in Tehran, Iran, were characterised using scanning electron microscopy (SEM) and high-performance liquid chromatography coupled with photodiode array detector (HPLC–DAD) and high-resolution mass spectrometry (HPLC-HRMS). The results showed that natural plant dyes including madder, indigo/woad and tannins were used to dye wool and linen fibres with different size and quality. Furthermore, the beige colour was identified to have been achieved by plants from a Rhamnus specie (Persian berries) rarely reported from Coptic textiles. Mixtures of the dyes were also identified in the textiles consistent with what we know from Coptic textiles. Both stylistic and technical studies suggest that these textiles have been woven some time between the fourth and the seventh century AD.

Since the second half of the 19th century, the world of textile production was radically changed both in terms of esthetics and of the performances leading to industrial products whose chemical properties were totally unknown and unexplored. Stage costumes are typical examples of multi-material art objects where different natural and synthetic materials were used to fulfil specific purposes. This research was performed in the framework of a diagnostic and restoration campaign of dresses of two Federico Fellini’s movies (“Il Casanova” and “Roma”). For the characterization of the textile fibers, Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Pyrolysis Gas Chromatography coupled with Mass Spectrometry (Py-GC/MS) were employed. The structure of the metallic threads was investigated by Scanning Electron Microscopy coupled with Energy-Dispersive X-ray Spectroscopy (SEM-EDX). Dye identification was carried out by High Performance Liquid Chromatography coupled with Diode Array Detector and mass spectrometry (HPLC-DAD, HPLC-ESI-Q-ToF). The analytical approach adopted allowed us to fully characterize the costumes composed of natural, synthetic and artificial fibers dyed with complex mixtures of last generation synthetic dyes. The results collected were fundamental to fine-tune an effective restoration aimed at minimizing the damages due to ageing, inaccurate home-made restoration interventions, or poor conservation conditions.

Synthetic textiles are constituents of heritage objects and garments often displayed in museum collections or preserved in archives, presenting unprecedented and specific conservation challenges. These issues need to be addressed assessing degradation processes, and developing targeted restoration and preventive conservation practices. The present work aims at characterizing the composition of high fashion garments and design textiles by Nanni Strada conserved in the archives of Nanni Strada Design Studio (Milan). To identify the chemical composition of the fibers used for the manufacturing, and to investigate the degradation processes affecting the objects, the materials were investigated by Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), Evolved Gas Analysis coupled to Mass Spectrometry (EGA-MS), and multi-shot Pyrolysis coupled to Gas Chromatography and Mass Spectrometry (Py-GC/MS). The results will contribute to a better knowledge of the chemical properties of the textiles produced in the 1970s, and to plan conservation and exhibition strategies.

Textile fibers have represented an important resource for mankind throughout all human history. In fact, ancient cultures employed them not just to produce clothes, but also for expressing their habits and traditions. Based on the chemical composition, textile fibers are classified as natural, artificial, and synthetic. The analysis of textile fibers can be very challenging, so it is crucial to find new analytical tools capable of identifying them and studying their behavior in the environment. The collected information can be transferred in many different fields, such as the industrial sector, forensic science, environmental science, and heritage science. In the present study, the capability of Pyrolysis coupled to Gas Chromatography and Mass Spectrometry (Py-GC/MS), and Evolved Gas Analysis coupled to Mass Spectrometry (EGA-MS) to discriminate textile fibers was tested. The first part of the study was addressed to the analysis of pure samples to build a detailed database by highlighting the main differences in the chromatographic profiles. Then, three textile blends of known composition were investigated, and the results compared with those acquired by Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy (ATR-FTIR). Eventually, the information obtained from the reference materials was exploited for the study of textile samples collected from the stage costumes of the lyrical opera 'I Puritani' directed by Franco Zeffirelli in 1961. The EGA-MS and Py-GC/MS results, integrated with those obtained by optical microscopy, allowed us to deepen the characterization of the historical samples.

Iron gall inks have been among the most used writing materials after carbon black, thus representing an important element of the historical and artistic heritage of our society. Crucially, the preservation of manuscripts and drawings is influenced by the presence of these inks, leading to conservation issues related to paper degradation and text fading. Besides all the advances obtained in paper conservation, the study of iron gall ink’s behaviour and ageing is still an important topic, which requires investigation through an accurate molecular characterisation to produce reliable models. In the present work a micro-destructive method based on liquid chromatography techniques (HPLC-DAD and HPLC-ESI-Q-ToF) has been optimised starting from a model gallic acid-based ink. An in-depth study of the behaviour of the ink in time was performed by natural and artificial ageing tests, monitored by colorimetry, showing the autoxidation of gallic acid to ellagic acid in the prepared mock-ups. The effect of relative humidity on ageing processes was also evaluated, allowing us to determine different intermediates depending on the environmental conditions. Finally, the analytical method developed was then successfully applied for investigating 19th–20th century historical ink samples, where one of the identified ageing markers was detected, besides the expected gallic and ellagic acids.

The paint media used by contemporary artists include a wide range of formulation of industrially produced paints based on synthetic resins and natural oils. We investigated the paint media used by the British artist Alexis Harding (born in 1973) in the painting “Quartet” (2003). The artwork exemplifies the artist's technique of mixing different paint media to obtain a sliding movement of the paint over the support, raising severe conservation issues and causing long-term instability of the paint. As a basis to develop a conservation strategy for the artwork, we investigated the composition of the paint by in situ non-invasive contactless external reflection infrared spectroscopy (ER-FTIR). The combination with laboratory analytical techniques applied on micro-samples allowed the identification of the pigments and the binders. The multi-analytical approach involved micro infrared spectroscopy (µFTIR), Raman spectroscopy, X-ray fluorescence (XRF), and mass spectrometric techniques coupled to chromatography (GC/MS and HPLC-ESI-Q-ToF) and analytical pyrolysis (Py-GC/MS and EGA-MS). The results of these micro-destructive investigations showed that the causes of the gliding of the paint are due the incompatibility between different materials superimposed by the artist: a fast drying alkyd paint and a mixture of siccative and non-siccative drying oils.

Eosin (Acid Red 87, C.I. 45380) is one of the most brilliant and challenging early synthetic dyes. In this study, an analytical approach based on high-performance liquid chromatography coupled with diode array and fluorescence detector and high resolution mass spectrometry was developed for testing different analytical columns and acids in the mobile phase. The ultra-sensitive approach, based on a chromatographic separation on a solid core and a porous shell Poroshell 120 EC-C18, allowed us to detect and characterize eosin and its synthesis by-products, such as the debrominated and methyl ester forms of eosin, in trace levels (the limit of detection for eosin is 0.13 ppb). The resulting miscellaneous composition of the eosin standard highlights the importance to determine the exact composition of the starting material to deal with, in order to avoid misinterpretations in aged or degraded samples. Finally, the successful identification of eosin in few grains (approximatively 20 x 40 mu m wide) of a faded Van Gogh's painting proved the strengths of our approach.

Geranium lake is an eosin-derived organic pigment highly employed by Van Gogh and his contemporaries. Its elusive behavior, observed in a large number of post-impressionism masterpieces, is of current concern for both conservators and heritage scientists. Herein, the lightfastness of Geranium lake within oil matrix has been investigated by means UV–Vis spectroscopic techniques and HPLC-DAD-HRMS with the final aim of understanding the degradation mechanism behind its marked bleaching. Accelerated photo-aging experiments irradiating with mono/polychromatic light have been carried out on oil paint models prepared with lead eosin-based lakes, in-house synthesized for this purpose according to available historical recipes, alone and in admixture with different white pigments namely, zinc oxide and basic lead carbonate. The aging experiment not only reproduced the fugitive nature of Geranium lake but also evidenced a reversible behavior during the preliminary stages of the light exposure. Succeeding targeted experiments employing monochromatic light as well as a simplified eosin-oil system in solution, corroborated by the wide literature regarding the photophysics of xanthene dyes, allowed us to propose a reasonable fading mechanism of eosin-based lakes, based on the key role played by linseed oil and environmental oxygen.

The identification of natural dyes in ancient textiles is a longstanding challenge for scientists; yet, the effort honours the skill and knowledge of master dyers by retracing traditional dyeing methods and assisting in conserving historical treasures for future generations. Here, the main constituents of selected native Japanese extracts from the roots of Lithospermum erythrorhizon and Scutellaria baicalensis, the barks of Phellodendron amurense and Morella rubra, the dried flower bud of Syzygium aromataticum, and the fruit of Terminalia chebula are determined by surface-enhanced Raman spectroscopy following traditional Japanese extraction methods. The analytical amalgamation of data from SERS examinations on crude extracts and on subsequently refiltered and diluted extracts provides further effective and sensitive results for the combined identification of napthoquinones (shikonin and alkanin), alkaloid (berberine), polyhydroxyflavonoids (baicalin/baicalein, myricetin/myricitrin), diarylheptanoids, allylbenzene (eugenol), and tannins (gallic/ellagic acid). The comparison of results from this analytical protocol with those achieved by the more traditional chromatographic and mass spectrometric method provides and questions data regarding generally accepted marker components and enantioselective discriminations that serve to enrich the database of biological sources of colouring materials to be used in determining historically important Japanese colorants and dyestuffs.

The cathedral in Odense, Denmark, has for nine centuries held the relics of the Danish King St Canute the Holy and his brother Benedikt. They were both murdered in the predecessor church at the site in AD 1086, and Canute was sanctified in already in AD 1100. The history of the relics has been that of turmoil at times, varying from initial worship of the Catholic believers, to being walled up and hidden away after the protestant reformation in AD 1536, and since the 19th Century on display as important heritage objects of national importance. In the present work we have characterised some of the textiles and analysed the air inside the glass showcases exhibiting the 11th Century wooden coffins holding the remains of St King Canute the Holy and his brother together with some precious textiles. Contrary to previous belief, we now prove that all the textiles analysed have the same age, which is consistent with the time of the enshrinement of the King and his brother in AD 1100. It is also shown that some of the textiles were treated with paraffin wax, most likely during attempts at conservation at the National Museum in the nineteenth century. The results of the air chemistry analyses show the problematic side of simultaneously storing of slowly decaying wood, fine textiles, and human bones in rather airtight environments. The wood continuously releases organic acids, the soaring concentrations of which are potentially harmful to the 11th Century textiles and probably also to the bones.

The object of this study is a wide selection of dyed cotton and camelid samples from an important collection of 2000-year-old Paracas textiles, now at the Museo Nacional de Arqueología, Antropología e Historia del Perú (MNAAHP; Lima; Peru) and at the National Museum of World Culture (NMWC; Gothenburg; Sweden). The threads, chosen as representative of the whole palette, were selected from eighteen different textiles. A combined spectroscopic and spectrometric analytical approach was selected to characterize the organic and inorganic composition of this wide set of samples. In particular, technical photography was used to gain a general overview of the samples, X-ray fluorescence (XRF) was employed for identifying the mordants and mapping the elemental distribution in the threads, while liquid chromatography coupled with diode array detector and with high-resolution mass spectrometry (HPLC–DAD, HPLC–HRMS) were used for characterizing organic dye composition. This study provides fundamental information on the mordants or other inorganic auxiliaries used in the dyeing processes, rarely investigated up to now, and to the varieties of vegetal sources employed in Paracas textiles. The widening of the Andean dyestuff database is highly important not only to acquire knowledge on Paracas culture, but also to ease the dye characterization of archaeological textiles from the Peruvian region and South American area in general.

Natural tannins from various plants have been used throughout human history in textile dyeing, often as mordant dyes. The ageing behavior of these dyes is a challenge in conservation science, requiring a thorough knowledge of the textile–mordant-dye system. In this work, we analyzed reference wool yarns dyed with natural tannins from oak gallnuts, walnut (Juglans regia), and catechu (Acacia catechu), after artificial ageing. To gain insights on the composition of the dyestuffs and on how they aged, an analytical procedure based on extraction with Na2EDTA/DMF (ethylenediaminetetraacetic acid/dimethylformamide) and high-performance liquid chromatography (HPLC) analysis using high-resolution mass spectrometry detection was used. Since conventional reversed-phase (RP) columns usually show poor retention efficiency of highly polar compounds such as tannins, an RP-amide embedded polar group stationary phase was used to achieve optimal retention of the most polar compounds. Tannins from oak gallnuts showed little degradation after ageing, while a significant increase in the content of hydroxybenzoic acids was observed for tannins from walnut and catechu. Finally, the analytical procedure was applied to characterize the tannin dyes in historical tapestries from the 15th to 16th century, and the results were discussed in comparison with the reference yarns.

Triarylmethine dyes, such as Methyl and Crystal Violets, Diamond green and Magentas, produced since the late nineteenth century, consist of complex mixtures of homologous compounds, often differing only for the presence or position of the same substituent on the aromatic rings. In this paper, Liquid Chromatography-High Resolution Mass Spectrometry (HPLC-HRMS) was used for the characterization of the profile of three dyes: Methyl Blue, Methyl Violet and Fuchsine. The comprehension of dye synthesis and production strategies was often achieved by analyzing the single components by diode array detector. Nevertheless, the nature of the individual components needs to be confirmed by tandem mass spectrometric techniques through the solving of the structural issues. The analysis of standards and reference materials by tandem high resolution mass spectrometry allowed us to identify peculiar fragmentation pathways for the components of magentas and methyl violet dyes. The results highlighted the importance to undertake the measurements both in negative and positive ionization mode. The elucidation of specific fragmentation patterns allows the discrimination between different classes of compounds, while the identification of specific fragment ions allows one to distinguish isomers belonging to the same series.

Modern art materials introduced since the end of XIX century include a large number of formulations of synthetic polymers and pigments, whose degradation processes and best preservation conditions are a major issue in heritage science. Analytical pyrolysis coupled with gas chromatography and mass spectrometry (Py-GC/MS) is widely used for the characterisation of polymeric materials and organic pigments, however the interpretation of the pyrograms obtained from samples containing different analytes is not straightforward. To improve our understanding on how these materials behave in complex matrices, we used evolved gas analysis coupled with mass spectrometry (EGA-MS) and multi shot Py-GC/MS to highlight and analyse the different fractions in a sample from a pop-art made of painted polyurethane (PU) foam. The study represents a proof of concept to evaluate EGA-MS potential in studying composite modern art materials in combination with multi-shot pyrolysis. The aim of the investigation was establishing the composition of the PU formulation, the paint binder and the pigments, thereby contributing to planning the stabilisation and conservation of the object. The polymers and the class of synthetic organic pigments present in the paint were assessed by determining their specific pyrolysis products and through comparisons with data in the literature. EGA-MS analysis provided both thermal and chemical information in one analytical run, so that we could select four temperatures for use in multi-shot Py-GC/MS analysis and thus to selectively study the different fractions evolved at different temperatures. Information on the various components of the mixture was obtained, including additives and organic pigments, separating them on the basis of their different thermal degradation temperatures. The multianalytical approach included also non-destructive ATR-FTIR and enabled us to characterize in detail different synthetic materials: polyether-based polyurethane produced by the

Wool has been the most widely used textile fiber in Europe since the Iron Age. It was largely employed to weave fabrics and clothes, and also for artistic purposes such as producing tapestries. This kind of artworks is among the most fragile of our heritage and is often in bad preservation conditions. Thus, the knowledge on the degradation processes of wool fibers is crucial for conservation issues. In the present study, we tested the potentialities of Pyrolysis coupled with Gas Chromatography and Mass Spectrometry (Py-GC/MS) and Evolved Gas Analysis coupled to Mass Spectrometry (EGA/MS) for the characterization of woolen reference samples, also subjected to artificial ageing, and of historical and archeological samples. The reference sheep wool yarns were prepared with different mordants and dyes, and have been analyzed both after storage in the dark for three years after preparation, and artificially aged for different time intervals and at different relative humidity values. We created a detailed pyrolysis database, evidencing the phenomena occurring with ageing and including camel wool for comparison. The ageing process undergone by the proteinaceous fraction of wool has also been investigated through monitoring specific fragment ions in the EGA profiles. The relevant parameters affecting the degradation process identified in this study match those assessed in previous investigations by different and complementary techniques, thus validating our approach. We proved that the novel approach based on EGA/MS is suitable for quickly assessing the conservation conditions of the woolen yarns and represents an advantage with respect to more time-consuming and complex methods, such as GC/MS or High Performance Liquid Chromatography (HPLC).

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.

The study and characterization of organic dyes in textiles, wastewaters, food, cosmetics and forensic specimens is an increasingly important field of research and a challenge for analytical chemistry. Sensitive and specific methods are required to determine molecular markers at very low concentrations and to detect and identify their relative degradation products. In this field, the present paper deals with the development of an extremely sensitive analytical strategy able to identify synthetic organic dyes even after ageing, such as photo-oxidation resulting in severe fading, by identifying specific stable markers. Rhodamine B (C.I. 45,170), belonging to the class of xanthenes, was chosen as representative of fugitive dyes of high commercial and historical importance, in the frame of a research promoted by the European platform IPERION-CH. The behaviour of Rhodamine B used as a dyestuff for wool yarns, subjected to accelerated photo-ageing, was investigated by chromatographic, spectroscopic and high resolution mass spectrometric techniques. The ultra-sensitive analytical method developed, based on core shell reverse phase analytical column separation, allowed us to characterize Rhodamine B oxidation products investigating their mass fragmentation and rationalizing the resulting ageing pathway. These degradation compounds, characterized in artificially aged reference wool yarns, confirmed to be valuable markers for the identification of Rhodamine B even in a complex historical textile matrix as a red Florentine velvet cope subjected to restoration in the 20th century.