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The consolidation of villager life in the Southern Andes implied profound transformations in human lifeways and groups’ relations with the landscape with the adoption of settled life and food production economies. Contributions from archaeological sciences can cast light into these research questions providing, for example, new information about patterns of susbsistence strategies. In this paper, we present the first organic residue analysis on ceramic containers of early villager societies of Northwestern Argentina (La Cienéga valley, ca. 200 BCE-900 CE) through two simultaneous lipid extraction methods (H2SO4/MeOH and CHCl3/MeOH). We aimed to put to test the existent characterization of the study area as a peripheric herding settlement evaluating the subsistence strategies and food economies of villager groups through the lens of absorbed organic residues in pottery. Preliminary evidence obtained in this article indicated a predominance of biomarkers associable to vegetable products in the vessels (i.e. maize) and a lower contribution of animal fats. Furthermore, a comparison and evaluation of the performance of each extraction method for specific compounds is given.

This paper reports the diagnostic research of deteriorated paint layers from three mural panels made by Almada Negreiros found in the Alcântara Maritime Station in Lisbon. The aim was to understand the main decay phenomena to aid future conservation works. The methodology comprised in-situ analyses by technical photography in Vis, Vis-RaK and UVF, p-OM and h-EDXRF; micro sampling; OM, SEM-EDS, μ-XRD, μ-Raman, µ-FT-IR and Py-GC/MS. Preliminary results show that all the paint layers analyzed are affected by salts (alkali sulphates) that over time have caused flacking, lack of cohesion, erosion, and lacunae. The light greenish/greenish bluish paint layers in all three panels are the most affected. No organic binders were identified, only the presence of vinyl polymer in glossy paint surfaces.

A diachronic, multi-analytical approach combining EDXRF, µFTIR, µRaman, SEM-EDS, and Py-GC/MS has been adopted with the aim to study for the first time the painting materials used to decorate Egyptian funerary masks and sarcophagi ranging from the Late Period to the Roman Period and stored in the Archaeological National Museum (MNA) and the Carmo Archaeological Museum (MAC) of Lisbon and the Natural History Museum of the University in Oporto (MNH-FCUP). Results indicate that yellow and red ochres, realgar, cinnabar, Egyptian blue, and Egyptian green were used as pigments while chalk served as the preparatory layer. Over the 1000-year timeline of the studied artifacts, the palette remained remarkably consistent with previous findings as exemplified by cinnabar being used for red pigments in samples only dated after the Ptolemaic period. The presence of Sn in Egyptian blue and Egyptian green pigments used in one sample suggests the use of recycled bronze scraps during pigment production. Black pigments in two Late Period masks were found to be produced by mixing Egyptian blue with red ochre suggesting either a hitherto unknown method for production of purple pigments in the Egyptian palette or, alternatively, an attempt to create a specific hue or shade of dark brown or black. The results of this study contribute to further expand the database of Ancient Egyptian painting materials while at the same time helping to valorize three important Egyptian collections in Portugal.

Comunicación oral presentada en EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4571, https://doi.org/10.5194/egusphere-egu22-4571, (2022), Forest fires are a recurrent ecological phenomenon in the Mediterranean basin. They induce molecular changes in soil organic matter (SOM) leading to immediate and long-term environmental consequences [1]. The SOM is of paramount importance as indicator of soil health [2]. Fire-induced changes in SOM include the alteration of biogenic chemical structures and the accumulation of newly formed ones, enhancing dynamics in the complex balance between the different C-types [2,3]. Therefore, understanding SOM molecular composition, before and after fire, is fundamental to monitor changes in soil health, as well as its natural or man-mediated recovery [3,4]. Our aim was to assess the molecular composition of organic matter in fire-affected leptosols, at two depths (0–2 and 2–5 cm) under different vegetation types located in the southwestern of Portugal (Aljezur, Algarve). The SOM characterization was conducted by analytical pyrolysis (Py-GC/MS), a technique based on the thermochemical breakdown of organic compounds in the absence of oxygen at elevated temperatures [5]. The Py-GC/MS has been found suitable for the structural characterization of complex organic matrices [4], providing detailed structural information of individual compounds considered fingerprinting of SOM. However, due to the relative high number of molecular compounds released by analytical pyrolysis, the use of graphical-statistical methods, such as van Krevelen diagrams, are usually applied to help monitoring SOM molecular changes produced by fire [3,4]. This work represents the first attempt to evaluate the fire effects in SOM using a detailed molecular characterisation of SOM under different vegetation canopies, recently affected by wildfire, in southern Portugal. References: [1] Naveh, Z., 1990. Fire in the Mediterranean – a landscape ecological perspective. In: Goldammer, J.G., Jenkins, M.J. (Eds.), Fire in Ecosystems Dynamics: Mediterranean and Northern Perspective. SPB Academic Publishing, The Hague. [2] González-Pérez, J.A., González-Vila, F.J., Almendros, G., Knicker, H., 2004. The effect of fire on soil organic matter—a review. Environ. Int. 30, 855–870. [3] Jiménez-Morillo, N.T., De la Rosa, J.M., Waggoner, D., et al., 2016. Fire effects in the molecular structure of soil organic matter fractions under Quercus suber cover. Catena 145, 266–273. [4] Jiménez-Morillo, N.T.; Almendros, G.; De la Rosa, J.M.; et al., 2020. Effect of a wildfire and of post-fire restoration actions in the organic matter structure in soil fractions. Sci. Total Environ. 728, 138715. [5] Irwin, W.J., 1982. Analytical pyrolysis—a comprehensive guide. In: Cazes, J. (Ed.), Chromatographic Science Series, 22: Chapter 6. Marcel Dekker, New York., This work was funded by national funds through FCT–Fundação para a Ciência e a Tecnologia (EROFIRE project, ref. PCIF-RPG-0079-2018). This research was funded by the European Union through the European Regional Development Funds in the framework of the Interreg V A Spain-Portugal program (POCTEP) through the CILIFO (Ref.: 0753_CILIFO_5_E) and FIREPOCTEP (Ref.: 0756_FIREPOCTEP_6_E) projects. In addition, this research was funded by the EU-FEDER co-funded project MARKFIRE (ref. P20_01073) from Junta de Andalucía. A.Z.M was supported by a CEECIND/01147/2017 contract from FCT, and a Ramón y Cajal contract (RYC2019-026885-I) from the Spanish Government (Ministerio de Ciencia en Innovación – MCIN).

Fig ( Ficus carica L.) is an excellent source of sugars, dietary fibers, minerals, vitamins, organic acids and phytochemicals. The aim of the present work was to investigate the effect of fig powder supplement, as a natural sweetener and flavoring agent, on the physicochemical, microbiological and sensory characteristics of goat’s milk yogurt. It aimed also to determine antioxidant capacity and volatile profile using gas chromatography/mass spectrometry (GC/MS) analysis. Pyrolysis-GC/MS (Py-GC/MS) was also used for the characterization of fig powder. Fig powder exhibited an important antioxidant activity against DPPH. Radical (IC50 = 1.92 ± 0.05 mg per mL). Volatile compounds, from several classes (acids, alcohols, aldehydes, esters, triterpenoids and others) were identified in fig powder. Py-GC/MS data revealed that degradation of fig powder macromolecules leaded to the formation of several aromatic and volatile compounds such as fatty acids, ketones, aromatic phenols, lactones among others. The addition of fig powder increased significantly (p

The organic extracts recovered from 14 potsherds of Dressel 20 oil amphorae collected from Pax Julia civitas (Lusitania) were analysed by GC–MS. Biomarkers of plant oils (saturated and unsaturated fatty acids, alcohols and alkanes arising from plant waxes) were identified in ten samples, and Pinaceae spp. pitch biomarkers were also identified in eight samples. The biomarkers identified in the studied Dressel 20 suggest that, even considering re-use, these amphorae should have been used for the same commodity, i.e., storage/transport of a plant oil. The presence of pitch in the amphorae could only be explained if it was used to reduce the porosity of the ceramic paste and minimise the oil diffusion through it.

The presence of stucco marble in the Portuguese architecture is not surveyed and studies addressing the materials used to produce it are almost inexistent. In this paper, the results of the multi-a...

The demand of new reactive fluorophores with improved photophysical characteristics for labeling oligonucleotide probes is growing. Sodium (E/Z)-4-(4-(2-(6,7-dimethoxycoumarin-3-yl)vinyl)-benzoyl)-2,3,5,6-tetrafluoro-benzenesulfonate (C392STP) is an amine-reactive fluorescent dye that has recently shown interesting photophysical properties. In this work, we investigate the possibility of: i) synthesizing it cheaply and easily; ii) using this reactive dye to synthesize single-labeled fluorescent oligonucleotides; and iii) applying the resulting fluorescently labeled oligonucleotides as fluorescence in situ hybridization (FISH) probes. According to the results obtained in this study, C392STP: i) can be synthesized through a low cost and simple pathway; ii) is an efficient building block for mono-labeling of oligomers with an efficiency as high as that of an amine-reactive Alexa Fluor® 488 dye supplied in a commercial oligonucleotide labeling kit. Furthermore, the RNA-FISH assays revealed that C392-mono-labeled probes containing standard carbon linkers (C6) exhibited effective performance as RNA-FISH probes. These findings evidenced the applicability of C392STP in labeling of biomolecules and bioimaging. The results invite the researchers to continue exploring other uses of this reactive dye for exploiting its potential in biological applications.

Archaeobotanical materials recovered from pottery vessels originating from the underwater archeological site of Gran Carro, located in Central Italy on the shore of Bolsena Lake, were analyzed to obtain new insight into the agricultural habits present in this Iron Age settlement. The archaeobotanical study of cereal remains was combined with analytical data obtained from an amorphous organic residue using optical microscopy, SEM-EDS, ATR/FT-IR and Py-GC/MS. The cereal remains of emmer wheat (Triticum dicoccum), barley (Hordeum vulgare), broomcorn millet (Panicum miliaceum), and foxtail millet (Setaria italica) were identified as the preferred crops used for food and/or fodder at the site. The presence of charred millets, which have been directly dated by AMS, confirms consumption at the site and adds to the little-known background of millet use in central Italy. The find of millets in a perilacustrine pile-dwelling during a period when the water level of the Bolsena Lake was several meters lower than at present, attesting to a general dry period, suggests that the cultivation of millets, complementing more productive crops of wheat and barley, may have been favored by the availability of a large seasonally dry coastal plain, characterized by poor and sandy soils unsuitable for more demanding cereals.

In the framework of the inter-disciplinary KongoKing project, a set of beads from archaeological excavations in the Democratic Republic of the Congo was analysed by means of a minimally invasive, multi-analytical approach based on micro-Raman spectroscopy. The full characterization of the materials, including glassy network, opacifiers and colorizers, was achieved thanks to the combination of data from handheld X-ray fluorescence, variable pressure scanning electron microscopy coupled with energy-dispersive X-ray spectrometry, micro-Fourier transform infrared spectroscopy and pyrolysis coupled to gas chromatography and mass spectrometry. The obtained chemical information was used to fill the existing gap in the chemical study of beads from Western Central Africa. The cobalt-rich blue beads were found to be of Central European origin, while the copper-rich turquoise beads were manufactured using distinct copper sources. Cadmium yellow and cadmium red are the colourants responsible for the bright colours of bead types 10 and 12, respectively. The type 12 beads were found to be composed of glass covered with a waxy layer tentatively identified as Japan wax. Prosser-moulded bead type 9 was coloured by means of a chrome–tin pigment, while a combination of Mn and Fe is responsible for the black colour of the type 47 beads. Cuprite is most likely responsible for the red hue of glass layers from type 14. The dark palm green exterior of the type 17 bead was produced by using a combination of Cu and Fe compounds; iron was the only chromophore detected in the Indian red decoration. Copyright © 2017 John Wiley & Sons, Ltd.

Magnetite nanoparticles (MNPs) have been evaluated for inhibiting microbial growth and biofilm for- mation. In this study the effect of the nanocomposite Moroccan propolis extract / MNPs acting against methicillin resistant strains of Staphylococcus aureus (MRSA) was evaluated. Chemical composition of propolis was established by pyrolysis coupled to gas chromatography and mass spectrometry method (pyrolysis GC/MS). MNPs were obtained through the co-precipitation method. The fabricated nanostruc- ture was characterized by X-ray Diffraction (DRX), Transmission Electron Microscopy (TEM), and Fourier Transform-Infrared Spectroscopy (FTIR). TEM of MNPs provided a particle average size of 15 nm, FTIR spectral analysis enabled a fast way of identification of MNPs, attesting the occurrence of the different combinations. The use of MNPs loaded with propolis and the antibiotic chloramphenicol at Minimum Inhibitory Concentration (MIC) value inhib- ited the bacterial growth of MSSA (methicillin susceptible strain of S. aureus ) and MRSA strains. After the treatment with MNPs-OA-P-CLo nanocomposite (MNPs with oleic acid, propolis and chloramphenicol), the disruption of the bacterial cell was observed by TEM. The combination of propolis and chlorampheni- col in free form at MIC value largely impaired both MSSA and MRSA strains as, after 2 h of treatment, no viable cells of MRSA 2 and MRSA 16 were recovered. Hence, the results elucidated a new antibac- terial nanocomposite synthesis, for possible applications as prospective nanoantibacterial agents or drug carriers. Fundação para a Ciência e Tecnologia with the project UID/Multi/04 4 49/2013 (POCI-01-0145-FEDER-007649); UID/BIA/04325/2013–MEDTBIO, UID/BIM/04773/2013 CBMR, UID/QUI/04023/2016, UID/QUI/0 010 0/ 2013, CQE. info:eu-repo/semantics/publishedVersion

The authenticity and provenience of what is known as the Francisco Pizarro’s Banner of Arms, stored at the National Museum of Colombia and related to the Spanish conquest of the Inca Empire, has been the object of debate amongst both historians and conservation experts for the last two centuries. In this study, a multi-analytical approach has been adopted to assess if the materials used in the making of the banner were compatible with the historical period assigned by historians. 25 micro samples were collected in different sections of the banner and subjected to microscopic, chromatographic and spectroscopic techniques to characterize the materials. Selected samples were also subjected to radiocarbon dating analysis. Analytical results enabled the identification of silk as the main fabric used in the making of the banner; cochineal, brazilwood and indigo were used as natural dyes while metal threads were utilized for decorative purposes. Paper with animal adhesive was used as the supporting material. The manufacturing technique together with radiocarbon dating data suggest the banner to be an original textile from the 15-16th centuries, possibly made at the time of King Charles I of Spain.

This paper reports the results of a multi analytical research undertaken on a mural and on a panel painting altarpiece authored by Jose de Escovar in 1603, one of the most productive and controversial painters working for Evora Archiepiscopate at the end of the 16th century and beginning of the 17th century. The two paintings are among his first documented artworks in the region and the only case where both are still in their original architectural location - the Chapel of the Souls in the main church of Vila Nova da Baronia (30 km away from the city of Evora). Jose de Escovar is a well-known mural painter but not much is still known about his other skills. To better define his craftsmanship, comparison of technical features and painting materials employed on both supports and paint layers was carried out using a multi-analytical setup for in situ analyses and laboratory characterization. The analytical campaign comprised technical photography (UVF-Vis-IR), portable EDXRF, OM, XRD, SEM/EDS, µ-Raman, µ-FT-IR and py-GC/MS. The results showed that although Jose de Escovar was considered a minor painter, he was clearly acquainted with both painting techniques and the use of different materials in accordance with the pictorial specifications and traditions at the time in Europe.

The objective of the present work was to develop strategies for increasing the shelf-life of red raspberries (Rubus idaeus L.), by preventing microorganism growth.; Results: Fruits coated with alginate plus lemon essential oil (0.2%) or orange essential oil (0.1%) after 15 days of storage had less red skin than the remaining samples. The less red color verified in these samples was also coincident with the lower concentration of anthocyanins at the end of the experiment as well as the lower capacity for scavenging ABTS free radicals or quenching singlet oxygen. Cyanidin and pelargonidin glucosides were found in raspberries fruits. The edible coatings supplemented with the essential oil of orange either at 0.1% or 0.2% were very efficient for controlling yeast and mold growth after 15 days of storage. To control the development of aerobic mesophilic bacteria the use of essential oil of lemon 0.2% and essential oil of orange 0.1% were the most efficient.; Conclusion: The application of the film improved post-harvest quality of raspberry, since the addition of essential oils of citrus films promoted to the inhibitory effect of fungi and bacteria growth after 15 days of storage, without changing quality parameters. © 2016 Society of Chemical Industry.; © 2016 Society of Chemical Industry.

This article describes the results of a multi-analytical research carried out on the mural paintings from Evora Cathedral, one of the oldest and most prominent monuments of Evora city. The paintings were a late 16th Century addition to the cathedral's northern transept chapel and are attributed to the painter Jose de Escovar, whose painting workshop was remarkably active in the so-called golden age of mural paintings in southern Portugal. The aim of the study was to reconstruct the paintings’ life story through a materials science perspective by discerning the material characteristics of the original and overpaint campaigns. The analytical setup comprised technical photography (TP) in the visible and UV light, Vis-Spectrophotometry, optical microscopy (OM) complemented with scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDS), micro Fourier transform infrared spectrometry (µFT-IR) and pyrolysis–gas chromatography (Py-GC/MS) analyses of the collected samples. Results show that the original paint layers were executed with a combination of fresco and secco techniques, using a very simple chromatic palette composed of earth pigments, mercury sulphide, calcium carbonate and green copper based pigments. The paintings were heavily retouched and overpainted using earth pigments, smalt, Prussian blue, zinc white and lead white. Furthermore, the analyses of the cross-sections taken from the stuccoed frames revealed a first decorative campaign made with gold and silver alloy. © 2016 Wiley Periodicals, Inc. Col Res Appl, 2016

This work presents the results of the analysis of the organic materials (red lakes and binders) from the flesh tones, wings, and vests of the angels from the mural paintings from the Charola of the Convent of Tomar. Pyrolysis coupled to gas chromatography and mass spectrometry (Py-GC/MS) was selected for the identification of binders, and liquid chromatography coupled to diode array and MS detection (LC/DAD/MS) was used for the identification of lakes in the red paint layers. © 2015 Wiley Periodicals, Inc. Col Res Appl, 2015

Two gilded miniature portraits on copper support from the Evora Museum collection (Portugal) were examined and analysed by stereomicroscopy, μ-Raman spectroscopy, SEM–EDS, portable-XRF (pXRF), μ-FTIR spectroscopy and liquid chromatography coupled to diode array and mass spectrometry detection (LC-DAD-MS). Both portraits, one of a gentleman and the other of a lady, are notable paintings of comparable richness, which present several areas painted or covered with gold (namely, gold dust to compose and highlight different ornaments and gold leaf to cover the back of one of the portraits). The gold dust, the gold leaf and the materials used in the gilding technique were investigated non-invasively and non-destructively using stereomicroscopy, SEM–EDS, pXRF and μ-FTIR. The other materials of the paintings, like the inorganic pigments and extenders, were successfully identified by μ-Raman spectroscopy, while the organic red pigment cochineal lake was positively identified by LC-DAD-MS. Overall, the materials identified in these 17th century paintings are broadly consistent with those mentioned in the painting treatises of that time, or with those reported in a very limited number of material studies focused on artworks of the same kind and period.

Goa Cathedral former altarpiece is one of the oldest set of paintings in India. The seven remaining paintings from the first altarpiece of Goa Cathedral, nowadays in the sacristy, are attributed by some art historians to Master Garcia Fernandes (act. 1514–1565), Portuguese painter from Lisbon workshop. The 16th century was the “Golden age” of Portuguese painting. In this context the Royal Lisbon workshop played a predominant role, where the activity of the painter Garcia Fernandes and his workshop can be distinguished. In this new approach, Goa paintings are being studied and compared with other works in Portuguese territory attributed to this same painter, as St. Bartholomew altarpiece from the chapel of Bartolomeu Joanes in Lisbon Cathedral. The stratigraphic study allowed to compare ground layers, pigments and binders which, were characterized using complementary analytical and imaging techniques: (X-ray Fluorescence spectrometry (XRF), Infrared Reflectography (IRR), Infrared Photography (IRP), Macro Photography (MP), micro-X-ray Diffraction (μ-XRD), Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS), Raman micro-spectroscopy (μ-Raman), Fourier Transform Infrared micro-spectroscopy (μ-FTIR), Pyrolysis gas chromatography mass spectrometry (PY-GC/MS). This work brought a new insight on the techniques and materials used in this Masterpiece and highlighted the conclusion that Goa Cathedral former altarpiece must be a Portuguese production.

Opuntia ficus‐indica fruits have an important nutritional value and show several biological properties. This work studied the fruit physicochemical characteristics of two wild ecotypes (“Green” and “Orange”) and two cultivars (“Rossa” and “Gialla”) from Portugal. The results showed that the largest and heaviest fruits were those from ecotype “Orange,”, whereas the wild ecotype “Green” had fruits with firmer flesh. The fruit peels of cultivars “Rossa” and “Gialla” presented the highest fibre content. Glucose was the major carbohydrate in the fruits, particularly in the peels. Malic acid was the sole organic acid in both peels and pulps of all samples. The betacyanins’ content was higher in fruits of the “Rossa” cultivar, and the higher betaxanthins’ content was present in the peel of the cultivar “Gialla.” Peels of all samples generally had higher amounts of betalains than the pulps. The peel was a better scavenger of DPPH and ABTS free radicals than the pulp. PRACTICAL APPLICATION: The wastes of diverse food industries have revealed the presence of bioactive compounds with added value. The fruits of Opuntia ficus‐indica are appreciated for possessing biological attributes, nevertheless the peel generally is not used. The present work shows that the pigments (betalains) are predominantly found in the peel. Moreover, the in vitro antioxidant activity was also higher in this part of the fruit, independent on the ecotype or cultivar studied. Such results might trigger the interest for these residues from which pigments and bioactive compounds can be extracted, and, as extracts, can be used in diverse domains particularly in food and pharmaceutical industries.

In this work, a study on a set of paintings from the most significant altarpiece assigned to Master Jorge Afonso (c. 1470–1540) painting workshop is presented. This altarpiece is composed by fourteen paintings made to the church of Convento de Jesus, in Setubal, Portugal, and was made circa 1517–19/1530, according to art-history. This set of paintings is compared to one of the other most important Portuguese altarpieces from the 16th century: the panels of the Round Church of the Convento de Cristo, in Tomar, made circa 1510–1515. The aim of this study is to characterize the wooden support, pigments, ground layers materials and technique used in Jorge Afonso workshop by means of complementary analyses. A dendrochronological approach was made in order to corroborate (or not) the historical date initially assigned. Infrared photography (IRP) and reflectography (IRR) allowed the study of the underdrawing technique and macro photography (MP) was used to recognize overlapping layers technique. Cross-sections from the paintings were examined by optical microscopy (OM), and analyzed by μ-X-ray diffraction (μ-XRD), Energy Dispersive X-ray Fluorescence spectroscopy (EDXRF), Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDS), micro-Raman spectroscopy (μ-Raman), micro-Fourier Transform Infrared spectroscopy (μ-FTIR), Pyrolysis Gas Chromatography Mass Spectrometry (py-GC/MS). The characterization of the palette and ground layers and the study of the overlapping of paint layers brought a new insight of the adopted painting techniques by the most important group of painters working in Portugal in the 16th century - the Lisbon workshop, leaded by Master Jorge Afonso.

Wool samples collected from thirteen Arraiolos carpets from the 17th–19th century belonging to the National Museum of Ancient Art (NMAA, Lisboa, Portugal) collection were analysed to identify the natural dyes and mordants employed in the traditional dyeing process, in a way to complement and improve actual knowledge on this rugs. Natural dyes were extracted from Arraiolos historical wool fibres using a mild extraction method, followed by high-performance liquid chromatography with diode array and mass spectrometry detection (HPLC-DAD-MS) for compound identification. Colourimetry was used to measure colour parameters in all historical samples. Quantification of mordants in the historical fibres was carried out by inductively coupled plasma-mass spectrometry (ICP-MS). Weld, indigo, spurge flax, brazilwood, madder and cochineal were identified as dye sources in the fibres. Alum was the most commonly used mordant, but the presence of iron and zinc was also detected in some darker samples. The use of madder and cochineal is not referred in the available historical dyeing recipes. This study also proved that the actual visual perception of these carpets is strongly affected by the natural dyes photodegradation, which was mostly unaccounted for before.

Gregorio Lopes (c. 1490–1550) was one of the most prominent painters of the renaissance and Mannerism in Portugal. The painting “Mater Misericordiae” made for the Sesimbra Holy House of Mercy, circa 1535–1538, is one of the most significant works of the artist, and his only painting on this theme, being also one of the most significant Portuguese paintings of sixteenth century. The recent restoration provided the possibility to study materially the painting for the first time, with a multianalytical methodology incorporating portable energy-dispersive X-ray fluorescence spectroscopy, scanning electron microscopy–energy-dispersive spectroscopy, micro-X-ray diffraction, micro-Raman spectroscopy and high-performance liquid chromatography coupled to diode array and mass spectrometry detectors. The analytical study was complemented by infrared reflectography, allowing the study of the underdrawing technique and also by dendrochronology to confirm the date of the wooden panels (1535–1538). The results of this study were compared with previous ones on the painter’s workshop, and significant differences and similitudes were found in the materials and techniques used.

Este estudo teve como objetivo a identificação dos materiais utilizados na produção de um ícone pós-bizantino pertencente à coleção do Museu de Évora. Este ícone, representando o “Imperador Constantino e a sua mãe Helena manifestando a Cruz”, foi datado como sendo do século X. Através de uma abordagem analítica diversificada, combinando exames de área com técnicas espectroscópicas, tentámos confirmar a sua datação. Os resultados obtidos sugerem que será provavelmente um ícone dos finais do século XVII ou do século XVIII.

Wool samples were dyed with madder and alum, copper, and iron salts at different concentration by pre-mordanting (MD) and simultaneous mordanting (M + D) procedures. Samples were artificially aged to identify the influence of the mordant on the madder chromophores photodegradation. A set of analytical techniques was used for complete characterisation of the dyed fibres before and after light exposure, which included colour and chromophore analysis (colourimetry and LC-ESI-MS/MS analysis), determination of mordant ions amounts in the fibres (FAAS and ICP-OES analysis), morphological characterisation of the fibres and punctual chemical analysis (SEM-EDS studies). Fibre colour hue was found to be dependent on the mordant ion nature, mordant bath concentration and dyeing procedure. Mordant ion quantification showed that the uptake of metal ion by the fibres is relatively small, with the Cu ion presenting the highest affinity for the fibre. MD method yields fibres with higher amounts of metal ions and larger chromophore chromatographic peak areas corresponding, in general, to stronger colour hues. Photodegradation was more severe in alum mordant samples and in the first 480 h of light exposure. Chromophore degradation rates are unequal and dependent on the mordant nature, contributing for colour changes observed after light exposure.

Geometry optimization of free alizarin, purpurin and luteolin and coordinated Fe(II) complexes was performed at DFT/B3LYP level. TD-DFT spectra were also calculated for free and coordinated alizarin and luteolin. For the Fe(II) complexes several spin multiplicities have been calculated and quintuplet spin structures were found to be the most stable. In the luteolin-Fe(II) complex, the coordination of the chromophore with the iron leads to a decrease in the lower energy band. In the case of luteolin complex, a new band emerges due to interactions between the delocalized π electrons of the luteolin molecule with the d metal orbitals.

Uma disputa entre cinco dos melhores pintores douradores de Évora deu origem à realização de uma extensa documentação sobre a técnica, os materiais e os preços em vigor em Évora, no ano de 1729. A rivalidade entre o mestre Filipe de Santiago, responsável pelo douramento do conjunto de talha da Igreja da Misericórdia, e a equipa liderada por Manuel da Maia que executou o douramento do retábulo da capela-mor da Igreja da Cartuxa, obrigou os comitentes a redigirem os contratos com um rigor inusual, já que ambos os mestres não aceitavam a possibilidade de serem examinados pelo oponente. A caracterização físico-química do douramento e das camadas de policromia de ambos os altares, realizada no âmbito do projecto GILT-Teller (www.gilt-teller.uevora.pt), permite-nos uma aproximação à cultura pictórica do período. Como é reportado nos contratos, o douramento da talha dourada foi enriquecido com carnações, estofado e “regraxos”. Estas técnicas foram utilizadas de maneira muito semelhante em ambos os conjunto da Igreja da Misericórdia e no Convento de Scala Coeli dos monges cartuxos de Évora. Os resultados documentais e analíticos dessa investigação confirmam a existência de uma cultura comum e pouco diferenciada entre as principais oficinas de Évora.

This paper describes a mini-project developed with 10th grade Portuguese students where, by using an experimental activity involving the use of natural dyes to colour wool, students acquired a better understanding of the concepts and relationship between the colour, the electromagnetic spectrum, and chemical bonding. As demonstrated by the results of a laboratory activity interest survey, the interdisciplinary nature of the mini-project contributed to raise student awareness to the existing relationship between science, culture and daily life, promoting their overall interest in scientific topics.

Onion skins (Allium cepa L.) and hydrated potassium aluminum sulfate were used to dye wool samples. The main chromophores associated with this natural dye source, quercetin and quercetin-4′-O-glucoside, were identified in the dye bath and in wool extracts by high-pressure liquid chromatography (HPLC) equipped with a diode array detector (DAD) with the help of standards. Two procedures were used to extract dye molecules from dyed wool prior to HPLC-DAD qualitative analysis and the analytical methodology used was discussed in terms of the analysis of historical textile pieces dyed with natural sources.

Brazilwood was used in this work to dye wool mordanted with different amounts of copper(II) sulfate, alum and iron(II) sulfate. Two different dyeing methods were used: premordanting (MD) and simultaneous mordanting (M+D) procedures. In order to evaluate the influence of the mordant ion in the brazilein chromophore photodegradation, samples were subjected to artificial light ageing. Color measurements were made and, for the first time, LC-DAD-ESI-MS was used for chromophore analysis of the dyed fibers before and after light exposure. Mordant ion quantification was done after fiber acid digestion, by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and flame atomic absorption spectroscopy (FAAS). Mordant metal ion, mordant bath concentration and dyeing procedure were found to have strong influence in the wool fiber hues. Color variation was more pronounced in the alum dyed samples. Overall, mordant quantification showed that the amount of metal ions found in the fibers is very small when compared to the original concentrations of the dyeing bath, being Cu the ion with greater affinity for the wool fibers. MD dyeing procedure yielded fibers with larger amounts of mordant metal ions and higher chromophore peak areas. Higher amounts of brazilein were extracted from wool mordanted with copper(II) sulfate. Finally, chromatographic analysis of the brazilwood dyed samples before and after light exposure resulted in the detection of Type C compound as an outcome of the photodegradation process.

The efficiency of eight different procedures used for the extraction of natural dyes was evaluated using contemporary wool samples dyed with cochineal, madder, woad, weld, brazilwood and logwood. Comparison was made based on the LC-DAD peak areas of the natural dye's main components which had been extracted from the wool samples. Among the tested methods, an extraction procedure with Na(2)EDTA in water/DMF (1:1, v/v) proved to be the most suitable for the extraction of the studied dyes, which presented a wide range of chemical structures. The identification of the natural dyes used in the making of an eighteenth century Arraiolos carpet was possible using the Na(2)EDTA/DMF extraction of the wool embroidery samples and an LC-DAD-MS methodology. The effectiveness of the Na(2)EDTA/DMF extraction method was particularly observed in the extraction of weld dye components. Nine flavone derivatives previously identified in weld extracts could be identified in a single historical sample, confirming the use of this natural dye in the making of Arraiolos carpets. Indigo and brazilwood were also identified in the samples, and despite the fact that these natural dyes were referred in the historical recipes of Arraiolos dyeing, it is the first time that the use of brazilwood is confirmed. Mordant analysis by ICP-MS identified the widespread use of alum in the dyeing process, but in some samples with darker hues, high amounts of iron were found instead.

Arraiolos tapestries are probably one of the richest artistic Portuguese expressions in terms of textile heritage. It is difficult to date the beginning of the production of rugs in Arraiolos (Southern Portugal), but they were already produced in the late 1600's as they are listed in the inventories of Portuguese aristocratic households in the beginning of the 18th century. Sensitive detection techniques play an increasing role in the chemical investigation of historical objects since the knowledge derived from the chemical composition of materials is of upmost importance for textile conservation and restoration purposes. Textiles deteriorate due to natural causes like heat, radiation, mechanical stress, moisture, microbiological and enzymatic attack. Deterioration of materials causes breakdown of the molecular structure and results in a loss of strength, extensibility and durability, discoloration and fading which affects the appearance of the textiles.

Cassis, a commercial powder obtained from blackcurrant juice (Ribes nigrum L.), was used to optimize the anthocyanin extraction by matrix solid-phase dispersion (MSPD) and by sea sand disruption method (SSDM). The optimum eluent conditions were 5.0 mL of MeOH/H2O (1:1, v/v) at pH 2. The extracts were analyzed by HPLC with diode-array detection (DAD) and the extraction efficiency was evaluated by statistical comparison (analysis of variance, ANOVA-single factor) of the compounds peak areas. The extraction efficiency for the MSPD procedure was dependent on the chemical nature of the C18 material but the optimized procedure yielded results similar to those obtained by the inexpensive sea sand disruption method (SSDM). This procedure also compared favorably to a previously published liquid-liquid extraction method. The optimized sea sand method was then used in the anthocyanin extraction from red grapes (Vitis vinifera L.) and strawberries (Fragaria ananassa D.) yielding chromatographic profiles similar to those reported in the literature for these products.