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1.
Sci Rep ; 13(1): 12170, 2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37500707

RESUMO

From the Pioneer Era of the aviation to World War I the evolution of aircraft technology and chemical synthesis enabled a unique coexistence of traditional craftsmanship, artistic decoration practices, and technological advancements. The study of the materials used in these early years of aviation is still an uncharted territory: a vast portion of remaining planes has been partially or completely repaired and restored, usually by total replacement of the fabric. The Italian biplane Ansaldo A.1 (1918) is a fighter aircraft and is one of the few planes in the world that still preserves its own original materials. In the last years, the fabric sections of the airplane have started to become brittle and loose cohesion, severely compromising the integrity of the aircraft, and resulting in a general alteration of the pictorial layers of the painted sections. A chemical investigation was undertaken to unveil the materials, and to elucidate the causes of the degradation. This study presents one of the first steps into the study of early historical aircrafts, defining the background for the conservation plans to preserve these objects for future generations.

2.
Molecules ; 27(19)2022 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-36234913

RESUMO

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.


Assuntos
Microscopia de Força Atômica , Microscopia de Força Atômica/métodos
3.
J Appl Microbiol ; 133(3): 1843-1856, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35822846

RESUMO

This study is part of a comprehensive investigation that was performed in regard to a case of alterations on a carbographic ribbon used in a typewriter that was found and seized by inner security operations of the Arma dei Carabinieri, Italy. Thirty-six coded scripts possessing potentially and criminally liable content were present on the tape; however, only the 6th and 7th scripts exhibited alterations of an uncertain nature. The study included sampling that was performed under sterile conditions of a large surface area of carbographic ribbons. A protocol based on physico-chemical, microbiological, and biomolecular tools was established. Preliminary results revealed the presence of fungal contamination that was primarily located on the inner surface of the 6th and 7th scripts on the black carbographic ribbon. One fungal strain was isolated and identified by universal ITS-PCR primer and rDNA sequencing as Alternaria infectoria strain NIS4. Fungal growth was monitored for 3 weeks in the laboratory under different environmental conditions (temperature, open-closed system, and substrate). The A. infectoria NIS4 strain exhibited the best growth at 28°C under a closed system with RH near saturation. We also noted that the fungal growth was abundant at 15°C. Moreover, this fungus (a potential human pathogen) possessed the ability to colonize the surface of the new carbographic ribbon even when using mineral medium; however, this only occurred in a closed system environment and not in open systems due to rapid desiccation. Under our experimental conditions, the A. infectoria NIS4 strain could degrade gelatin as an organic matter present in trace amounts that are often used as a binder in a carbographic ribbon emulsions. The results revealed that the isolated microorganism was the major biological candidate capable of altering the investigated carbographic ribbon; however, these alterations could only occur under favourable environmental conditions. AIMS: Identify the cause of microbial alterations on a carbographic ribbon in a typewriter used in a hypogean Italian criminal house named "covo." METHODS AND RESULTS: The isolation and identification of biodeteriogens (Alternaria infectoria NIS4) were performed using both culture-dependent and-independent methods, including ITS regions-primed PCR and rDNA techniques. Environmental scanning electron microscopy (ESEM) and optical observations were also performed. Growth tests and biodeterioration simulation tests on carbographic ribbons at the lab scale were performed under different environmental conditions. The A. infectoria NIS4 strain exhibited biodeterioration activity on carbographic ribbons under environmental conditions that were extremely favourable for growth. A high ability to colonize carbographic ribbon surfaces with fast and abundant growth at both 15°C and 28°C under lab-scale conditions at RH near saturation was observed. CONCLUSIONS: In this forensic case study, the ability of the isolated micromycetes A. infectoria NIS4 strain to colonize and induce alterations and degradation in a carbographic ribbon stored under indoor environmental conditions was examined. When favourable conditions change over time, the risk of microbial colonization and the damage produced by the fungal biodeterioration processes on the synthetic material objects has been confirmed. SIGNIFICANCE AND IMPACT OF STUDY: The current study contributes to the knowledge of biodeterioration processes in carbographic ribbon and the responsible agents, and our study provides an example of how environmental microbiology can also aid in forensic studies.


Assuntos
Alternaria , Microbiologia Ambiental , Alternaria/metabolismo , DNA Ribossômico , Humanos , Reação em Cadeia da Polimerase
4.
Materials (Basel) ; 15(11)2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35683126

RESUMO

A macroscopic lithological study and physical (hardness, size, weight) investigations, coupled with laser-induced breakdown spectroscopy (LIBS) and X-ray fluorescence (XRF) chemical analyses of three egg- and one pear-shaped polished black stones, exposed in the library of the child home of the famous poet Giacomo Leopardi, at Recanati (Italy), were carried out. They are characterized by different sizes: two with the same weight of 16.9 kg and the two smaller ones of 5.6 kg each, corresponding to multiples of standard roman weights (drachma and scrupulum). These features and the presence of some grooves on the rock artefacts, probably for grappling hooks, suggest an original use as counterweight for the four black stones herein classified as amphibole-bearing serpentinites whose lithologies are far away from Recanati (probably coming from geological outcrops in Tuscany). The four serpentinite stones closely match with the so-called Lapis Aequipondus used in antiquity by the Romans as counterweights. Due to the presence of lead rings or iron hooks in these stones, Lapis Aequipondus were also used for martyrdoms during the persecution of Christians in the Roman period, attached to the necks of martyrs that were then thrown in the wells or attached to the ankles of hanging bodies. This is the reason why these stones are also known as Lapis Martyrum, venerated with the relative martyrs, in several churches of Rome. The four black stones investigated probably arrived at Recanati from Rome after the middle of the 19th century. In the past, Christians also called Lapis Martyrum the "devil's stones" (Lapis Diaboli). This could also be the reason for the popular belief that black stones cannot be touched by people, except those of the Leopardi dynasty. This work contributes to the cultural heritage of Leopardi's child home, as the four black stones had never been investigated.

5.
Environ Sci Pollut Res Int ; 29(14): 20694-20710, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34741740

RESUMO

This study integrates the complex research conducted on the sources of brown discolorations that occur on marble statues (fifteenth century) of the Church of Orsanmichele in Florence (Italy). They underwent conservative interventions in the past and the brownish discolorations on their surfaces strongly altered the clear tone of the marble. In this study, Carrara marble model specimens were treated with organic and inorganic substances (non-pasteurised milk; linseed oil; walnut oil; ammonium oxalate; microcrystalline wax; beeswax; milk + linseed oil; and milk + ammonium oxalate + linseed oil) to simulate their effects on the stone. Some of the substances were commonly used in the past (as on the Orsanmichele statues) but most of them are still used in many countries. The treated specimens were exposed to natural and artificial ageing. The main results of the research were (i) the specimens treated with linseed oil, milk + linseed oil, and milk + linseed oil + ammonium oxalate showed a severe change of colour after either artificial or natural ageing; (ii) an extensive polymerisation of the organic substances occurred; (iii) calcium oxalate and several oxidised diacylglycerols (DAGs) and triacylglycerols (TAGs) were the last chemical products of the oxidation processes induced by ageing; (iv) Maillard reaction, producing brownish coloration, likely occurred in specimens containing milk as a result of the interaction between sugars and proteins.


Assuntos
Carbonato de Cálcio , Óleo de Semente do Linho , Animais , Carbonato de Cálcio/análise , Ácidos Graxos/análise , Itália , Óleo de Semente do Linho/análise , Leite/química , Oxirredução
6.
Molecules ; 25(7)2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32276409

RESUMO

The first synthetic polymers were introduced as constituents of everyday life, design objects, and artworks at the end of the 19th century. Since then, the history of design has been strictly connected with the 20th century evolution of plastic materials. Objects of design from the 20th century are today a precious part of the cultural heritage. They raise specific conservation issues due to the degradation processes affecting synthetic polymer-based plastics. Museums and collections dealing with the conservation of design objects and modern materials need to base their conservation strategies on compositional data that reveal the formulations of historical plastics and their decay processes. Specific and specifically optimized analytical tools are thus needed. We employed flash analytical pyrolysis coupled with gas chromatography and mass spectrometry (Py-GC/MS) and evolved gas analysis coupled with mass spectrometry (EGA-MS) to characterize "historic polymeric materials" (HIPOMS) and heritage plastics at the molecular level with high chemical detail. This approach complements non-invasive spectroscopic diagnosis whenever it fails to obtain significant or complete information on the nature and the state of preservation of the materials under study. We determined the composition of several 20th century design objects (1954-1994) from the Triennale Design Museum of Milan (Triennale Milano - Museo del Design Italiano), which for different morphological, chemical, or physical reasons were unsuitable for characterization by non-invasive spectroscopy. EGA-MS proved capable for the study of the different fractions constituting heterogeneous micro-samples and for gaining an insight into their degradation processes from the contextual interpretation of thermal and mass-spectrometric data.


Assuntos
Plásticos/química , Pirólise , Cor , Cromatografia Gasosa-Espectrometria de Massas , Compostos Orgânicos/química , Propriedades de Superfície
7.
Talanta ; 212: 120800, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32113562

RESUMO

This work presents a method to characterize high molecular esters in beeswax and resinous substances based on the use of microwave-assisted extraction and flow injection analysis-high resolution mass spectrometry that combines the high efficiency of the extraction procedure with the advantages of high resolution mass spectrometry. This approach allows us to identify archaeological beeswax and plant resinous substances by the characterization of the survived intact high molecular weight components. By this way, several raw materials (beeswax, pine resin and pitch, and resin extracted from Euphorbia tirucalli) were studied and used as reference substances. The procedure was then tested on an adhesive dated 44-42 ka BP recovered from Border Cave (KwaZulu-Natal, Africa), allowing us to detect the high molecular weight species even after almost 50,000 years, and then used to chemically investigate unknown archaeological adhesives from Antinoopolis (Egypt), dated to the 4th-5th century AD. The results allowed us to extend our knowledge on the long-term behavior of beeswax and resinous substances.

8.
Talanta ; 207: 120323, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31594618

RESUMO

A fast non-destructive approach based on the use of portable selected ion flow tube-mass spectrometry (SIFT-MS) was used for the first time to characterize organic materials in archaeological artifacts. The high sensitivity, specificity and selectivity SIFT soft chemical ionization mass spectrometry enabled us to investigate the composition of organic residues collected from ancient Egyptian findings in order to demonstrate the robustness of the techniques with different matrices. In addition, we tested SIFT-MS directly on an archaeological Egyptian amphora to prove its suitability as a completely non-invasive technique. Parallel investigations on all the samples were performed by GC/MS analysis to correlate and confirm the data obtained by SIFT-MS. The possibility of using a portable mass spectrometer on an excavation site or in a museum would be a significant step forward in the non-invasive analysis of organic archaeological materials, enabling archeologists and conservators to obtain real-time information on the molecular composition of organic residues.

9.
J Am Soc Mass Spectrom ; 30(11): 2250-2258, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31489561

RESUMO

The identification at molecular level of organic materials in heritage objects as paintings requires in most cases the collection of micro-samples followed by micro-destructive analysis. In this study, we explore the possibility to characterize natural and synthetic resins used as paint varnishes by mean of non-invasive analysis of released volatile organic compounds (VOCs) through selected ion flow tube-mass spectrometry (SIFT-MS). SIFT-MS is a portable direct mass spectrometric technique that achieves the analysis of VOCs at trace levels in real time, by controlled ultra-soft chemical ionization using eight different chemical ionization agents. We tested the portable instrumentation on different reference resins used as paint varnishes, both natural (mastic, dammar, and colophony) and synthetic (Paraloid B67, MS2A, Regalrez 1094, and polyvinyl acetate), to evaluate the possibility to acquire qualitative data for the identification of these materials in heritage objects avoiding any sampling. This new analytical approach was validated by comparison with the traditional approach for VOCs analysis based on solid phase micro extraction-gas chromatography/mass spectrometry (SPME-GC/MS) analysis. The results demonstrate the use of SIFT-MS as an in situ non-invasive and non-destructive mass spectrometric technique to identify organic materials, such as paint varnishes.

10.
Molecules ; 24(12)2019 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-31234558

RESUMO

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.


Assuntos
Espectrometria de Massas , Taninos/análise , Taninos/química , Fibra de Lã/análise , Animais , Juglans/química , Espectrometria de Massas/métodos , Estrutura Molecular , Peso Molecular , Nozes/química , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/química
11.
Angew Chem Int Ed Engl ; 57(25): 7313-7323, 2018 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-29521446

RESUMO

The molecular characterization of organic materials in samples from artworks and historical objects traditionally entailed qualitative and quantitative analyses by HPLC and GC. Today innovative approaches based on analytical pyrolysis enable samples to be analysed without any chemical pre-treatment. Pyrolysis, which is often considered as a screening technique, shows previously unexplored potential thanks to recent instrumental developments. Organic materials that are macromolecular in nature, or undergo polymerization upon curing and ageing can now be better investigated. Most constituents of paint layers and archaeological organic substances contain major insoluble and chemically non-hydrolysable fractions that are inaccessible to GC or HPLC. To date, molecular scientific investigations of the organic constituents of artworks and historical objects have mostly focused on the minor constituents of the sample. This review presents recent advances in the qualitative and semi-quantitative analyses of organic materials in heritage objects based on analytical pyrolysis coupled with mass spectrometry.

12.
Sci Rep ; 8(1): 3935, 2018 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-29500428

RESUMO

Cereals were very important in ancient diets, however evidence from archaeological sites of the vessels used for processing or storing cereals is comparatively rare. Micro-organisms, as well as chemical-physical effects can easily degrade cereals during the burial period. This can lead to a complete cereal decay and to serious difficulties in estimating the intensity of use of the cereals by ancient populations. Here, we present a novel biomarker approach entailing the detection of secondary lipid metabolites produced by ergot fungi (genus Claviceps), which are common cereal pests. The aim was to identify the original presence of Gramineae and to indirectly establish if vessels were used for cereal storage/processing. The fatty acid and TAG-estolide profiles of the remains from more than 30 archaeological vessels were investigated by gas chromatography/mass spectrometry (GC/MS) and high performance liquid chromatography/high resolution mass spectrometry (HPLC/ESI-Q-ToF). The detection of lipids derived from ergot in archaeological and historic contexts rests on its complex chemistry, providing a unique and relatively recalcitrant chemical signature for cereals. This research demonstrated that the combination of our innovative biomarker approach along with environmental and archaeological evidence can provide unprecedented insights into the incidence of cereals and related processing activities in ancient societies.


Assuntos
Arqueologia , Claviceps/química , Grão Comestível/química , Lipídeos/análise , Biomarcadores/análise , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Itália , Espectrometria de Massas por Ionização por Electrospray/métodos
13.
Anal Bioanal Chem ; 409(17): 4233-4245, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28484806

RESUMO

Wood artefacts undergo complex alteration and degradation during ageing, and gaining information on the chemical composition of wood in archaeological artefacts is fundamental to plan conservation strategies. In this work, an integrated analytical approach based on innovative NMR spectroscopy procedures, gel permeation chromatography and analytical pyrolysis coupled with gas chromatography/mass spectrometry (Py-GC-MS) was applied for the first time on archaeological wood from the Oseberg collection (Norway), in order to evaluate the chemical state of preservation of the wood components, without separating them. We adopted ionic liquids (ILs) as non-derivatising solvents, thus obtaining an efficient dissolution of the wood, allowing us to overcome the difficulty of dissolving wood in its native form in conventional molecular solvents. Highly substituted lignocellulosic esters were therefore obtained under mild conditions by reacting the solubilised wood with either acetyl chloride or benzoyl chloride. A phosphytilation reaction was also performed using 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholan. As a result, the functionalised wood developed an enhanced solubility in molecular solvents, thus enabling information about modifications of lignin, depolymerisation of cellulose and structure of lignin-carbohydrate complexes to be obtained by means of spectroscopic (2D-HSQC-NMR and 31P-NMR) and chromatographic (gel permeation chromatography) techniques. Py-GC-MS was used to investigate the degradation undergone by the lignocellulosic components on the basis of their pyrolysis products, without any pre-treatment of the samples. The application of all these combined techniques enabled a comprehensive characterisation of the whole cell wall of archaeological wood and the evaluation of its state of preservation. High depletion of carbohydrates and high extent of lignin oxidation were highlighted in the alum-treated objects, whereas a good preservation state was found for the untreated wood of the Oseberg ship. Graphical abstract ᅟ.


Assuntos
Arqueologia/métodos , Parede Celular/química , Fósseis , Cromatografia Gasosa-Espectrometria de Massas/métodos , Espectroscopia de Ressonância Magnética/métodos , Células Vegetais/química , Madeira/química , Celulose/análise , Cromatografia em Gel/métodos , Fósseis/história , História Antiga , Líquidos Iônicos/química , Lignina/análise , Solubilidade
14.
Talanta ; 161: 62-70, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27769456

RESUMO

Lipid binders have traditionally been determined in paintings by using gas chromatography/mass spectrometry (GC/MS) to identify the characteristic profiles and ratios of fatty acids . However, the presence of mixtures in contemporary and modern oil paints makes the GC/MS determination of fatty acids insufficient to fully characterize the lipid binding media. In this study we prove that triacylglycerol (TAG) profiling by high-performance liquid chromatography with high-resolution tandem mass spectrometry, using ESI in positive and negative ionization modes is highly effective. We exploited this analytical approach to study the curing and degradation processes undergone by six plant oils used in the formulation of media in modern paints, using both natural and artificial ageing experiments. We believe that is the first time that a negative ionization mode has been applied for this purpose and that a survey with HPLC-ESI-Q-ToF has been carried out to study the ageing kinetics of plant oils. TAG profiling enabled us to study the evolution over time of the constituents of modern oils, with respect to curing and ageing. The data analyzed in this study demonstrate that our approach is efficient to study the oxidation of TAGs during ageing. The data also improve current knowledge on the properties of vegetable oils, which could lead to the development of new paint materials and conservation treatments for modern and contemporary works of art.


Assuntos
Pintura/análise , Óleos de Plantas/análise , Triglicerídeos/análise , Cromatografia Líquida de Alta Pressão , Ácidos Graxos/análise , Luz , Óleos de Plantas/química , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem , Temperatura , Titânio/química , Triglicerídeos/química
15.
J Am Soc Mass Spectrom ; 27(11): 1824-1834, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27582117

RESUMO

This study deals with the identification of anthraquinoid molecular markers in standard dyes, reference lakes, and paint model systems using a micro-invasive and nondestructive technique such as matrix-assisted laser desorption/ionization time-of-flight-mass spectrometry (MALDI-ToF-MS). Red anthraquinoid lakes, such as madder lake, carmine lake, and Indian lac, have been the most widely used for painting purposes since ancient times. From an analytical point of view, identifying lakes in paint samples is challenging and developing methods that maximize the information achievable minimizing the amount of sample needed is of paramount importance. The employed method was tested on less than 0.5 mg of reference samples and required a minimal sample preparation, entailing a hydrofluoric acid extraction. The method is fast and versatile because of the possibility to re-analyze the same sample (once it has been spotted on the steel plate), testing both positive and negative modes in a few minutes. The MALDI mass spectra collected in the two analysis modes were studied and compared with LDI and simulated mass spectra in order to highlight the peculiar behavior of the anthraquinones in the MALDI process. Both ionization modes were assessed for each species. The effect of the different paint binders on dye identification was also evaluated through the analyses of paint model systems. In the end, the method was successful in detecting madder lake in archeological samples from Greek wall paintings and on an Italian funerary clay vessel, demonstrating its capabilities to identify dyes in small amount of highly degraded samples. Graphical Abstract ᅟ.

16.
Top Curr Chem (Cham) ; 374(1): 6, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27572989

RESUMO

Gas chromatography/mass spectrometry (GC/MS), after appropriate wet chemical sample pre-treatments or pyrolysis, is one of the most commonly adopted analytical techniques in the study of organic materials from cultural heritage objects. Organic materials in archaeological contexts, in classical art objects, or in modern and contemporary works of art may be the same or belong to the same classes, but can also vary considerably, often presenting different ageing pathways and chemical environments. This paper provides an overview of the literature published in the last 10 years on the research based on the use of GC/MS for the analysis of organic materials in artworks and archaeological objects. The latest progresses in advancing analytical approaches, characterising materials and understanding their degradation, and developing methods for monitoring their stability are discussed. Case studies from the literature are presented to examine how the choice of the working conditions and the analytical approaches is driven by the analytical and technical question to be answered, as well as the nature of the object from which the samples are collected.


Assuntos
Arqueologia , Cromatografia Gasosa-Espectrometria de Massas/métodos , Carboidratos/análise , Lipídeos/análise , Compostos Orgânicos/análise , Pinturas , Pirólise
17.
Artigo em Inglês | MEDLINE | ID: mdl-27267284

RESUMO

In the occasion of the celebrations for the 150th anniversary of the founding of Italy (1861-2011), it was decided to analyse the artwork "The Italian Flag" (La Bandiera Italiana) created by the artist Fernando Melani (Pistoia, 1907-1985), one of the precursors of the Poor Art artistic movement in Italy. This project is a follow-up to a previous study which was mainly focused on the pigments and dyes found in his home-studio. The main goal of this paper is to identify a correct diagnostic plan, based on the use of a combination of non-invasive and micro-invasive methodologies, in order to determine the state of preservation and define the best conservation procedures for a contemporary artwork. Visible, infrared and infrared false colour images as well as the Fibre Optic Reflectance Spectroscopy (FORS) technique were applied in situ to analyse The Italian Flag. Laser Induced Breakdown Spectroscopy (LIBS), Fourier Transform Infrared (FT-IR) and micro-Raman spectroscopies, Pyrolysis-Gas Chromatography/Mass Spectroscopy (Py-GC/MS), High Performance Liquid Chromatography with Diode Arrays Detection (HPLC-DAD) and Mass Spectrometric Detection (HPLC-ESI-Q-ToF) were all applied to three small samples detached from the three painted (green-blue, white and red-yellow, respectively) areas of the flag. The combination of the data obtained with all these techniques made possible a comprehensive understanding of both the chemical composition and physical behaviour of the materials used by the artist and supported curators in defining the preventive conservation of this artwork.

18.
J Nat Prod ; 79(4): 845-56, 2016 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-26981624

RESUMO

Dammar is a triterpenoid resin containing a volatile fraction, a monomeric fraction, and a high-molecular weight fraction. Although the low-molecular-weight components comprising sesquiterpenoids and triterpenoids have been extensively studied, the nature of the macromolecular components is still not fully understood, and different and sometimes contradictory theories have been proposed. The aim of this paper is to clarify the nature of the macromolecular components of dammar resin. A multianalytical approach was adopted based on thermoanalytical-thermogravimetric analysis (TGA), and thermogravimetric analysis coupled with Fourier transform infrared spectroscopy (TGA/FTIR)--and mass spectrometric techniques-direct exposure mass spectrometry (DE/MS), pyrolysis coupled to gas chromatography and mass spectrometry (Py/GC/MS), flow injection analysis electrospray ionization mass spectrometry (FIA/ESI/MS), and gas chromatography/mass spectrometry (GC/MS). The data indicate that the oligomeric fraction comprises triterpenoids bound through ester bonds, and that these triterpenoids are the same as those found in the free terpenoid fraction. The oligomeric fraction also includes triterpenoids containing carbonyl moieties, such as formyl groups, thus suggesting that these are involved in the esters in their corresponding enolic form.


Assuntos
Resinas Vegetais/química , Triterpenos/química , Triterpenos/isolamento & purificação , Ésteres , Cromatografia Gasosa-Espectrometria de Massas , Estrutura Molecular , Peso Molecular , Espectrometria de Massas por Ionização por Electrospray , Espectroscopia de Infravermelho com Transformada de Fourier , Espectrometria de Massas em Tandem
19.
Appl Spectrosc ; 70(1): 174-85, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26767643

RESUMO

A multi-analytical approach was used to study the constituent materials, manufacturing technique, and state of conservation of a contemporary sculpture. This sculpture, entitled Nuredduna, was created by Aligi Sassu in 1995 and is located in the "Bellariva garden" in Florence (Italy). Fourier transform infrared spectroscopy (FT-IR), optical and electronic microscopy (OM and SEM-EDS), X-ray diffraction (XRD), and portable X-ray fluorescence (XRF) highlighted the multi-layered structure of the statue: fiberglass and an overlay of different layers (gel coat) applied with an unsaturated polyester resin added with aggregate materials and bromine compounds. A top-coat in acrylic black varnish, used as a finish, was also found. The combination of these materials with their different compositions, environmental impact, and even vandalism have negatively affected the state of conservation of Nuredduna, causing the loss of strata in its lower parts (legs and feet).

20.
Anal Chim Acta ; 896: 177-89, 2015 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-26482002

RESUMO

Modern oil paints, introduced at the beginning of the 20th century, differ from those classically used in antiquity in their chemical and compositional features. The main ingredients were still traditional drying oils, often used in mixtures with less expensive oils and added with several classes of additives. Consequently, detailed lipid profiling, together with the study of lipid degradation processes, is essential for the knowledge and the conservation of paint materials used in modern and contemporary art. A multi-analytical approach based on mass spectrometry was used for the study of original paint materials from Munch's atelier, owned by the Munch Museum in Oslo. The results obtained in the analysis of paint tubes were compared with those obtained by characterizing a paint sample collected from one of the artist's sketches for the decoration of the Festival Hall of the University of Oslo (1909-1916). Py-GC/MS was used as screening method to evaluate the presence of lipid, proteic or polysaccaridic materials. GC/MS after hydrolysis and derivatization allowed us to determine the fatty acid profile of the paint tubes, and to evaluate the molecular changes associated to curing and ageing. The determination of the fatty acid profile is not conclusive for the characterization of complex mixtures of lipid materials, thus the characterization of the triglyceride profiles was performed using an analytical procedure based on HPLC-ESI-Q-ToF. This paper describes the first application of HPLC-ESI-Q-ToF for the acquisition of the triglyceride profile in a modern paint sample, showing the potentialities of liquid chromatography in the field of lipid characterization in modern paint materials. Moreover, our results highlighted that the application of this approach can contribute to address dating, authenticity and conservation issues relative to modern and contemporary artworks.

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