Raman Spectroscopy Applied to the Study Cretaceus Fossils

8/10/2019 Raman Spectroscopy Applied to the Study Cretaceus Fossils

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ABSTRACTS

BOOK OF

International Congresson the Application ofRaman Spectroscopyin Art and Archaeology

2-6 September 2013

7th


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7thInternational Congress on theApplication of Raman Spectroscopyin Art and Archaeology


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B O O K O F A B S T R A C T S

7th International Congress on the

Application of Raman Spectroscopy

in Art and Archaeology

Ljubljana, Slovenia, 2th6th September 2013


6/2176RAA 2013

Book of Abstracts

7th International Congress on the Application of Raman Spectroscopy in Art and A rchaeology (RAA 2013),

Ljubljana (Slovenia), 2th6th September 2013

Publisher: Institute for the Protection of Cultu ral Heritage of Slovenia

Editors: Polonca Ropret, Nadja Ocepek

Editorial Board: Klara Retko, Lea Legan, Tanja pec, rtomir Tavzes

Print: Birograka BORI d.o.o.

Copies: 400

Copyright RAA 2013 and the Authors

All Rig hts Rese rved

Ljubljana 2013

No part of the material protecte d by this copyright may be reproduced or utilized in any form or by a ny means, electronic or mechanical, includ-

ing photocopying, recording or by any storage or retrieval system, without wr itten permission from the copyr ight owners.

The publication is published with the nancial support of t he Ministry of Cu lture, and is not payable.

CIP - Kataloni zapis o publikaciji

Narodna in univerzitetna knjinica, Ljubljana

543.424.3:7(082)

543.424.3:902(082)

INTERNATIONAL Congress on t he Application of Raman Spectroscopy in Art and Archaeology (7 ; 2013 ; Ljubljana)

Book of abstracts / 7th International Congress on the Application of Raman Spectroscopyin Art and Archaeology, Ljubljana (Slovenia), 2th-6th September 2013 ; [editors Polonca Ropret, Nadja Ocepek]. - Ljubljana : Institute for the

Protection of Cultural Heritage of Slovenia, 2013

ISBN 978-961-6902-38-0

1. Ropret, Polonca, kemik

268489728

REPUBLIC OF S LOVENIA

MINISTRY OF CULTURE


7/2177 Book of Abstracts

The use of Raman spectroscopy for identifying and studying the material component of the objects of art andantiquities has ourished in recent years. The increasing importance of the application of Raman spectroscopyin art and archaeology is illustrated by an increasing number of research papers published each year, and by thescientic conferences and sessions that have been dedicated to this research area in the past decade.The RAA conferences promote Raman spectroscopy and play an important role in the increasing eld of its ap-

plication in Art and Archaeology. The RAA is an established biennial international event. It brings togetherstudies from diverse areas and represents dedicated work on the use of this technique in connection to the eldsof art-history, history, archaeology, palaeontology, conservation and restoration, museology, etc. Furthermore,the development of new instrumentation, especially for non-invasive measurements, has received a great atten-tion in the past years. These prominent, international events have a long tradition. Previously they were held inLondon (2001), Ghent (2003), Paris (2005), Modena (2007), Bilbao (2009), Parma (2011), and this year (2013)in Ljubljana.

The RAA 2013 conference received over 100 high quality contributions from different research laboratories allover the world, and this book of abstracts presents their latest advancements. One of the important topics isstudies of deterioration induced by different environmental factors, such as biodeterioration, pollution, light and

humidity exposure. The outcomes of these studies can give important information for designing safe conserva-tion restoration treatments and help in creating a better environment for cultural heritage objects, for theirstorage and display, all contributing to increasing of its sustainability. A great number of research contributionsare presenting the latest achievements in the characterisation of traditional organic colorants by introducingnew solutions for Surface enhanced Raman spectroscopic studies. This is an important topic that contributes tounderstanding not only the composition of the organic colorants, but also their production processes. The ad -

vancements in metals characterisation give important information to understanding of their corrosion processesand/or deliberate patinations by artists, which can give important input in designing further corrosion inhibitionprocesses. A special topic is dedicated to the archaeometry research, from characterisation of ancient artefacts,their degradation processes, to nding possible solutions for their preservation. New, presented knowledge ongemstones characterisation, provenance, authenticity research, and furthermore, forensics applications, all attest

of the wide applicability of Raman spectroscopy. The latest innovations in Raman instrumentation is presentedby well known companies in the eld of Raman instruments, with a special emphasis in the development ofportable, non-invasive instruments. Many research laboratories are taking the advantage of non-invasive instru-ments in order to keep the full integrity of works of art. However, the interpretation of the results is often chal-lenging, which gives scientic contributions dealing with these questions a special, important place. Finally, theimportance of a comprehensive Raman database is emphasised, and the latest work of the Infrared and RamanUsers Group (IRUG) is presented, a database which we all help creating, and which can help in solving manyquestions that we all face.

We wish to thank all of the authors who submitted their latest research results and helped creating the scienticprogram of the RAA 2013 conference, as well as this Book of Abstracts.

On behalf of the organizing committee,Polonca Ropret,Research Institute, Conservation Centre,Institute for the Protection of Cultural Heritage of Slovenia


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Scientic Committee

Dr. Polonca RopretResearch institute, Conservation Centre,Institute for the Protection of Cultural Heritage of Slovenia

Dr. Danilo BersaniDipartimento di Fisica e Scienze della Terra,Universit degli Studi di Parma, Italy

Prof. Dr. Juan Manuel MadariagaDepartment of Analytical Chemistry, Faculty of Science and Technology,University of the Basque Country, Spain

Prof. Dr. Peter VandenabeeleResearch group in Archaeometry, Department of Archaeology,Ghent University, Belgium

Prof. Dr. Howell G. M. EdwardsCentre for Astrobiology and Extremophiles Research,School of Life Sciences, University of Bradford, UK

Prof. Dr. Pietro BaraldiDepartment of Chemical and Geological Sciences,University of Modena and Reggio Emilia, Italy

Dr. Sandrine Pags-CamagnaCentre de Recherche et de Restauration des Muses de France (C2RMF), France

Dr. Francesca CasadioThe Art Institute of Chicago, USA



Organizing Committee

Janez KromarDirector of Conservation Centre,Institute for the Protection of Cultural Heritage of Slovenia

Jernej HudolinHead of Restoration Centre,Conservation Centre,Institute for the Protection of Cultural Heritage of Slovenia

Dr. Polonca RopretHead of Research InstituteConservation Centre,Institute for the Protection of Cultural Heritage of Slovenia

Dr. rtomir TavzesResearch Institute, Conservation Centre,Institute for the Protection of Cultural Heritage of Slovenia

Tanja pecResearch Institute, Conservation Centre,Institute for the Protection of Cultural Heritage of Slovenia

Lea LeganResearch Institute, Conservation Centre,

Institute for the Protection of Cultural Heritage of Slovenia

Klara RetkoResearch Institute, Conservation Centre,Institute for the Protection of Cultural Heritage of Slovenia

Nadja OcepekResearch Institute, Conservation Centre,Institute for the Protection of Cultural Heritage of Slovenia


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List of accepted works with corresponding authors

PL: Plenary LectureOP: Oral PresentationP: Poster Presentation

Monday, September 2, 2013

ORAL SESSION 1Deterioration studies and organic materials

Raman Spectroscopy of ExtremophilicBiodeterioration: An Interface between Archaeologyand the Preservation of Cultural Heritage

Identication of endolithic survival strategies on stone

monuments

FT-Raman analysis of historical cellulosic bresinfected by fungi

Combined FT-Raman and Fibre-Optic ReectanceSpectroscopic Characterisation of Simulated MedievalPaint Films: a Chemometric Study of the Effects ofNatural and UV-Accelerated Ageing

Study of malachite degradation in easel (model)

paintings by spectroscopic analysis

Portable and laboratory analysis to diagnose theformation of eforescence on walls and wall paintingsof Insula IX, 3 (Pompeii, Italy)

Decorated plasterwork in the Alhambra investigated byRaman spectroscopy: eld and laboratory comparativestudy

Multi-technical approach for the study of French

Decorative Arts furniture and luxury objects

POSTER SESSION 1

Deterioration of lead based pigments on a fresco: amicro-Raman investigation

Investigation of colour layers in easel (model) paintingsinuenced by different ageing processes

Howell G. M. Edwards

Annalaura Casanova Municchia

Katja Kavkler

Anuradha Pallipurath

Tanja pec

Juan Manuel Madariaga

Ayora-Caada Mara Jos

Cline Daher

Ilaria Costantini

Klara Retko

PL1 20

OP1 22

OP2 24

OP3 26

OP4 27

OP5 29

OP6 31

OP7 33

P1 35

P2 36



Identication of copper azelate in 19th centuryPortuguese oil paintings: Characterisation of metalsoaps by Raman Spectroscopy

Raman study of pigment degradation due to acetic acidvapours

Investigating the sources of degradation in corrodedlead sculptures from Oratory Museum (Museu doOratrio), Brazil

Evora Cathedral: Pink! Why not?

Study of red biopatina composition on sandstonefrom a historical war Fort in La Galea (Biscay,north of Spain) by means of single point focusingRaman analysis and Raman Imaging combined with

microscopic observation

Raman and non invasive IR analyses of naturalorganic coatings: application to historical violin

varnishes

Characterization of green copper organometallicpigments and understanding of their degradationprocess in European easel paintings

Optical Microscopy and Micro-Raman studies of The

Hans Memlings Triptych The Last Judgment

Non-destructive micro-Raman and XRF investigationon parade saddles of italian renaissance

Phoenicians preferred red pigments: micro-Ramaninvestigation on some cosmetics found in Sicilyarchaeological sites

Raman microscopy and X-ray uorescence for therediscovering of polychromy and gilding on classicalstatuary in the Galleria degli Ufzi

Raman spectroscopic investigation of black pigments

Raman Spectroscopy and SEM-EDS Studies RevealingTreatment History and Pigments of the GovernmentPalace Tower Clock in Helsinki Empire Senate Square

Feasibility Study of Portable Raman Spectroscopy forCharacterization of Ground Material of Easel Paintings(Case Study: Sradar Asad-e Bakhtiary Painting ofKamal-al Molk)

Vanessa Otero

Alessia Coccato

Thiago Sevilhano Puglieri

Ana Teresa Caldeira


Cline Daher

Carlotta Santoro

Ewa Pita

Pietro Baraldi

Cecilia Baraldi

Pietro Baraldi

Alessia Coccato

Kepa Castro

Mohsen Ghanooni

P3 38

P4 40

P5 42

P6 44

P7 46

P8 48

P9 50

P10 51

P11 52

P12 54

P13 56

P14 58

P15 60

P16 62


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The Sibyls from the church of San Pedro Telmo: aspectroscopic investigation

Pigment identication of illuminated medievalmanuscripts by means of a new, portable Ramanequipment

Micro-Raman identication of pigments on wallpaintings: characterisation of Langus and Sternenspalettes

ORAL SESSION 2

RENISHAW: New Methods in Raman Spectroscopy Combining Other Microscopes for mineral and pigment

analysis

HORIBA JOBIN YVON: Advances in Ramaninstrumentation: explore new boundaries in Art and

Archaeology

NORDTEST: A portable 1064 nm Raman spectrometerfor analysis of cultural heritage items

BAYSPEC: Novel 1064 nm Dispersive RamanSpectrometer and Raman Microscope for Non-invasive

Pigment Analysis

Tuesday, September 3, 2013

ORAL SESSION 3Surface Enhanced Raman Spectroscopy in Artand Archaeology

Surface-Enhanced Raman Spectroscopy in Art andArchaeology

TLC-SERS of mauve, the rst synthetic dye

New photoreduced substrate for SERS analysis oforganic colorants

Laser Ablation Surface-enhanced RamanMicrospectroscopy

Marta S. Maier

Debbie Lauwers

Petra Belagi

Josef Sedlmeier

Romain Bruder

Alessandro Crivelli

Lin Chandler

Marco Leona

Maria Vega Caamares

Klara Retko

Pablo S. Londero

P17 64

P18 66

P19 68

OP8 70

OP9 72

OP10 73

OP11 75

PL2 78

OP12 80

OP13 82

OP14 84



Silver colloidal pastes for the analysis via SurfaceEnhanced Raman Scattering of colored historicaltextile bers: some morphological and spectroscopicconsiderations

Surface enhanced Raman spectroscopy for dyes andpigments Can non-invasive investigations become areality?

Surface Enhanced Raman Scattering of organic dyes ongold substrates prepared by pulsed laser ablation

Combining SERS with chemometrics: a promisingtechnique to assess historical samples with historicallyaccurate reconstructions

Characterization and Identication of Asphalts inWorks of Art by SERS complemented by GC-MS, FTIRand XRF

Study of Raman scattering and luminescenceproperties of orchil dye for its nondestructiveidentication on artworks

POSTER SESSION 2

Application to historical samples of in situ,extractionless SERS for dye analysis

Application of surface-enhanced Raman spectroscopy(SERS) to the analysis of red lakes in FrenchImpressionist and Post-Impressionist paintings

Surface-Enhanced Raman Spectroscopy (SERS)of historical dyes on textile bers: evaluation of anextractionless treatment of samples

Suitability of Ag-agar gel for the micro-extraction oforganic dyes on different substrates: the case study of

wool, silk, printed cotton and panel painting mock-ups

PB15 polymorphic distinction in paint samplesby combining micro-Raman spectroscopy andchemometrical analysis

Ambra Idone

Brenda Doherty

N. R. Agarwal

Rita Castro

Mara Lorena Roldan

Francesca Rosi

Ambra Idone

Federica Pozzi

Chiara Zafno

Elena Platania

Jolien van Pevenage

OP15 86

OP16 88

OP17 90

OP18 92

OP19 94

OP20 95

P20 96

P21 98

P22 100

P23 102

P24 104


14/21714RAA 2013

First identication of the painting technique in 18thCentury Transylvanian oil paintings using micro-Raman and SERS

Organic materials in oil paintings and canvas revealed

by SERS

Characterization of SOPs in acrylic and alkyd paints bymeans of -Raman spectroscopy

Synthetic Polymers and Cultural Heritage. Analyticalapproach by Raman spectroscopy

Raman monitoring of the sol-gel process on OTES/TEOS hybrid sols for the protection of historical glasses

Possible differentiation with Raman spectroscopybetween synthetic and natural ultramarine blues.Comparative analysis with the blue pigment of apainting of R. Casas (18661932)

Raman monitoring of the polymerization reaction of ahybrid protective for wood and paper

Reference Raman data of the artist palette tool for in-situ investigation of J. Matejko (18381893) paintings

Material analysis of the Manueline Foral Charters ofLous and Marvo

Materials and gilding techniques on plasterwork in theAlhambra (Granada, Spain)

Characterization of gypsum and anhydrite groundlayers on 15th and 16th centuries Portuguese painting

by Raman Spectroscopy, Micro X-ray diffraction andSEM-EDS

Identication of deteriorated pigments on wallpaintings from Lutrovska klet, Sevnica, Slovenia,using Raman spectroscopy and SEM-EDS

Characterization of middle age mural paintings: insitu Raman spectroscopy associated with differenttechniques

Oana-Mara Gui

Oana-Mara Gui

Marta Angehelone

Margarita San Andrs

L. de Ferri

A. R. De Torres

Laura Bergamonti

Iwona muda-Trzebiatowska

Antnio Candeias

Domnguez Vidal Ana

Antnio Candeias

Katja Kavkler

Julene Aramendia

P25 106

P26 108

P27 110

P28 112

P29 114

P30 116

P31 118

P32 119

P33 121

P34 123

P35 125

P36 128

P37 130



Raman microspectroscopic identication of pigmentsof newly discovered gothic wall paintings from theDominican Monastery in Ptuj (Slovenia)

Shot Noise Reduction through Principal Components

Analysis

ORAL SESSION 4Raman for characterization of metal artefacts

Raman investigation of articial patinas on recentbronze, protected by different azole type inhibitors inoutdoor environment

Micro-Raman Investigation on corrosion of Pb-Based

Alloy Replicas

Conservation diagnosis of weathering steel sculpturesusing a new Raman quantication imaging approach

Raman study of the salts attack in archaeologicalmetallic objects of the Middle Age: The case ofEreozar castle (Bizkaia, Spain)

Thursday, September 5, 2013

ORAL SESSION 5Raman Spectroscopy in Archaeometry

The Contribution of Archaeometry to Understandingof the Past Effects and Future Changes in the WorldHeritage Site of Pompeii (Italy)

Raman spectroscopy applied to the study of Cretaceousfossils from Araripe Basin, Northeast of Brazil

Raman spectroscopic analyses of~75. 000 year oldstone tools from Middle Stone Age deposits in SibuduCave, KZN, South Africa

Raman Spectroscopy in Archaeometry: multi-methodapproaches and in situ investigations: advantages anddrawbacks

Maja Gutman

J. J. Gonzlez-Vidal

Tadeja Kosec

Giorgia Ghiara

Julene Aramendia

Kepa Castro


Paulo T. C. Freire

Linda C. Prinsloo

Peter Vandenabeele

P38 132

P39 134

OP21 135

OP22 136

OP23 138

OP24 140

PL3 143

OP25 145

OP26 147

OP27 149


16/21716RAA 2013

Spectroscopic Analysis of Chinese Porcelain Excavatedin Clairefontaine (Belgium): Pigment Identication andDating

Characterization of ancient ceramic using micro-

Raman spectroscopy: the cases of Motya (Italy) andKhirbetal-Batrawy (Jordan)

Hispano-Moresque architectural tiles from theMonastery of Santa Clara-a-Velha, in Coimbra,Portugal: a -Raman study

The blue colour of glass and glazes in Swabian contexts(South of Italy): an open question

Spectroscopic characterisation of crusts interstratied

with prehistoric paintings preserved in open-air rockart shelters

POSTER SESSION 4

Micro-Raman on Roman glass mosaic tesserae

Raman and IR Spectroscopic Study of VitreousArtefacts from the Mycenaean to Roman Period: GlassyMatrix & Crystalline Pigments

The detection of Copper Resinate pigment in works ofart: contribution from Raman spectroscopy

Micro-Raman and internal micro-stratigraphicanalysis of the paintings materials in the rock-hewn church of the Forty Martyrs in ahinefendi,Cappadocia (Turkey)

Vibrational characterization of the new gemstonePezzottaite

FTIR-ATR and ESEM of wall paintings from the tombof Amenemonet (TT277), Qurnet Murai necropolis,Luxor, Egypt

Physico-chemical characteristics of Predynastic potteryobjects from Maadi Egypt

Jolien van Pevenage

Laura Medeghini

Vnia S. F. Muralha

Maria Cristina Caggiani

Antonio Hernanz

Claudia Invernizzi

Doris Mncke

Irene Aliatis

Clauda Pelosi

Erica Lambruschi

Mohamed Abd El Hady

Mohamed Abd El Hady

OP28 150

OP29 152

OP30 154

OP31 155

OP32 157

P40 159

P41 160

P42 162

P43 164

P44 166

P45 168

P46 170



Raman Database of Corrosion Products as a powerfultool in art and archaeology

MicroRaman as a powerful non-destructive techniqueto characterize ethonological objects from DAlbertis

Castle Museum of World Cultures in Genova

Micro ATR-IR study of pollutions affecting radiocarbondating of ancient Egyptian mummies

Raman Scanning of Biblical Period Ostraca

Analyses of pigments from 4th century B.C. theShushmanets tombs in Bulgaria

Raman Spectroscopic Study of the Formation of Fossil

Resins Analogs

Pigments from Templo Pintado (Pachacamac, Per)investigated by Raman Microscopy

Lithic tools raw materials recognition by Ramanspectroscopy of Palaeolitihic artifacts

Raman characterization on historical mortar. Crossingdata with XRD and Color Measurements

Roman ceramics from Vicofertile (Parma, Italy):micro-Raman study of the heat diffusion during theproduction process

Raman spectroscopic study on ancient glassbeads found in Thailand archaeological sites

Identication of Neolithic jade found in Switzerlandstudied using Raman spectroscopy: Jadeite vs.Omphacite jade

Raman Spectroscopy as useful tools for thegemmological certication and provenancedetermination of sapphires

Authentication of ivory by means of 1064 nm Ramanspectroscopy and X-ray uorescence spectrometry

Serena Campodonico

Serena Campodonico

Ludovic Bellot-Gurlet

Arie Shaus

Cristina Aibo

Margarita San Andrs

Dalva Lcia Arajo de Faria

Sonia Murcia-Mascaros

Dorotea Fontana

Elisa Adorni

Pisutti Dararutana

Marie Wrle

Simona Raneri

Alessandro Crivelli

P47 171

P48 173

P49 175

P50 176

P51 178

P52 179

P53 181

P54 183

P55 184

P56 185

P57 187

P58 188

P59 190

P60 191


18/21718RAA 2013

ORAL SESSION 6Characterization of Gems and Forensic

Applications

Characterization of emeralds by micro-Raman

spectroscopyRaman micro spectroscopy of inclusions in gemstonesfrom a chalice made in 1732

Spectroscopic investigation: impurities in azurite asprovenance markers

Implementation of scientic methods of ne artauthentication into forensics procedures: the case studyof Bolko II widnicki by J.J Knechtel

Raman analysis of multilayer automotive paints inforensic science: measurement variability and depthprole

Friday, September 6, 2013

ORAL SESSION 7Non-invasive Raman Investigation

The Art of non-invasive in situ Raman spectroscopy:

identication of chromate pigments on Van Goghpaintings

Characterisation of a new mobile Raman spectrometerfor in-situ analysis

On-site high-resolution Raman spectroscopy onminerals and pigments

Molecular characterization and technical study ofhistoric aircraft windows and head gear using portable

Raman spectroscopy

ROUND TABLE Ramanspectral database

The Infrared and Raman Users Group Web-basedRaman Spectral Database

Danilo Bersani

Miha Jerek

Lucia Burgio

Barbara ydba-Kopczyska

Danny Lambert

Costanza Miliani

Debbie Lauwers

Martin A. Ziemann

Odile Madden

Marcello Picollo

OP33 192

OP34 194

OP35 196

OP36 198

OP37 200

PL4 203

OP38 205

OP39 207

OP40 208

PL5 210


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Monday, September 2


20/21720RAA 2013

Raman Spectroscopy of Extremophilic Biodeterioration: AnInterface Between Archaeology and the Preservation of CulturalHeritage

Howell Gwynne M. Edwards1*

The identication of biological colonisation in archaeological artefacts and ancient art works representsmajor problems for the preservation of materials and objects of cultural heritage for conservationscientists and art restorers with the realisation that the deleterious effects of this colonisation can

be ongoing even when the artworks have been prepared for storage. The conservation strategies andcuration of biodegraded objects from archaeological sites are especially difcult to enforce when theincipient damage has yet to be made evident. Artefacts composed of biological materials are particularly

susceptible to biological degradation especially by extremophilic organisms which have developedsophisticated chemical protection strategies for survival in extreme environments which prove to

be toxic to other organisms. The application of analytical Raman spectroscopic techniques to thecharacterisation of the chemical composition of mineral and synthetic paint pigments, ceramics, resins,dyes, textiles and human skeletal remains is also now nding much interest in cultural heritage circles;during these studies it has become apparent that the spectral signatures of biological colonisations thatare responsible for the serious deterioration or degradation of archaeological artefacts are closely similarto those which one might expect to nd with remote robotic Raman spectroscopic instrumentation onplanetary surface and subsurface exploration rover vehicles for the detection of extinct or extant life.

The miniaturisation of Raman spectrometers for the detection of life signatures on planets and their

satellites in our Solar System is exemplied by the forthcoming ESA ExoMars mission to the planetMars which will specically search for extant or extinct life in the Martian subsurface geological recordthrough a powerful suite of instrumentation that includes a Raman laser spectrometer for the rst time.

A database of key Raman spectral signatures of species such as carotenoids, chlorophyll, scytoneminand other key protective biochemicals produced by terrestrial specimens of cyanobacterial and lichenextremophiles which exist in stressed hot and cold terrestrial environments such as the Atacama Desert,

Arctic meteorite impact craters, volcanic outcrops in Svalbard and the dry Valleys in Antarctica is beingcomplied to identify the presence of biological colonisation in suitable rock matrices. The adaptationof the mineralogy and the host geological matrices by the cyanobacterial colonies and their productionof protective biochemicals is a vital requirement for the survival strategy for biological growth andevolution. This is also the case for the biological colonisation of archaeological relics excavated from

a depositional environment and a readily available spectral database can hence be assimilated forthe identication and characterisation of areas of biological degradation in ancient artefacts whichmay be used to alert conservators to the urgent need for restorative and preservative strategies toprevent further ongoing specimen deterioration subsequent to supercial cleaning procedures beingundertaken.

The potential afforded by the reduction in size and increased portability of Raman spectrometersappeals to conservation scientists for the in situanalytical measurements that can be performed on

PL1

1Centre for Astrobiology and Extremophiles Research, School of Life Sciences,University of Bradford, West Yorkshire, UK, + 44 1274 233787, [email protected]
mailto:[email protected]:[email protected]



objects without the need for destructive sampling, often in inaccessible locations, and an awarenessthat the Raman spectral information can reveal the presence of biological agents that could causethe ongoing deterioration of a cultural object need to be recognised. Also, the unsightly growths ofcyanobacteria and lichen communities on exposed works of art such as wall paintings, statues andfrescoes can be very deleterious and damaging to artistic viewing; in this context, the ability of biological

colonies to attach themselves to mineral pigments which are often very hazardous and highly toxic tohumans, such as compounds of lead, copper, mercury, antimony and arsenic provides an example ofextremophilic behaviour which equally matches the strategies they have adopted to overcome extremesof temperature, pH, radiation insolation and barometric pressure elsewhere terrestrially.

Hence, in this presentation we shall explore some examples of the occurrence of biological colonisationof art works and artefacts in which Raman spectroscopy has provided novel information about theonset of degenerative processes which are often apparent spectroscopically before they are observed

visually; this affords the establishment of analytical Raman spectroscopy as an early warning monitorof biological degradation in an artefact which may therefore require urgent conservational treatmentto prevent further damage occurring and which will lend support to the apparently unrelated scientic

engagement between Raman spectroscopists working on space missions and in the eld of culturalheritage preservation.

- The examples used to illustrate this approach will be taken from the following cultural heritagecase-studies and scenarios;

- Lichen degradation of wall-paintings;- Biological colonisation of badly damaged frescoes undergoing restoration;- Degradation of human mummies from Egyptian Dynastic burials preserved in museum collections;- Biological invasion of grave sites and contributions to the mineral degradation of human skeletal

remains;- Denition of biological spectral signatures in archaeological excavations of human and mammoth

remains;

The impact of space mission derived data for key biological signatures on the identication of similarsignatures from biodegraded artefacts from archaeological excavations will inform future Ramanspectrosopic applications for such instruments in archaeological and cultural heritage site work andthe identication of biological and associated mineralogical materials which could advise and informfuture conservation protocols and approaches.

PL1


22/21722RAA 2013

Identication of endolithic survival strategies on stone monuments

Annalaura Casanova Municchia,1*Giulia Caneva,1Maria Antonietta Ricci,1

Armida Sodo1

A relevant aspect of stone bio-deterioration is the colonization by endolithic microorganisms thatpenetrate some millimetres or even centimetres into the rock. This phenomenon is mainly due to astrategy of protection from desiccation and high solar radiation.[13]

In the literature there are only few studies about the impact of endolithic microorganisms on stonemonuments, and on the ecological conditions favouring this kind of colonization. Additionally moststudies refer to colonization at extreme environmental conditions, such as cold and hot deserts.Nevertheless, the presence of endolithic microorganisms has been observed in stone monuments

in Temperate and Mediterranean climates, especially in comparably dry environments (e.g. verticalsurfaces of buildings exposed to sunlight).[46]

In recent years the study of endolithic organisms in extreme environments has been busted by severalastrobiological studies, aimed at nding a trace of life on Mars, where cold deserts, such as Antarcticaor the Arctic, have been proposed as the closest analogues to Martian on Earth. [79] Consequently,the interest for the development of techniques and protocols for the identication of endolithicmicroorganisms on stones is spread over a wide scientic eld.

We have used Raman spectroscopy to identify rock alteration and pigments traces produced by endolithicmicroorganisms as survival and adaption strategies to adverse conditions on stones monuments.Notably this technique can easily be implemented (and already is) in space missions.

Endolithic cyanobacteria can produce photo protective accessory pigments, such as scytonemin,parietin, calycin; they also mobilize some iron oxides to create a mineral screen layer on the rocksurface. In both cases they leave biological or geological traces on rock due to their metabolic activityor indirect effects.

We have performed the experiment on different rock samples, in order to investigate the impactof endolithic microorganisms on stone monuments from areas characterized by Temperate andMediterranean climates. In detail, the aim is to detect key biomarkers and geomarker providing anindicator of different adaptation strategies used in adverse condition and identifying the alterationsproduced on the substrate.

OP1

1 Department of Sciences, University of Roma Tre, Rome, Italy, +39 06 5757336374,[email protected]

Figure 1.Microphotographs of cross-section. a.) Sample of Church of Martvilib.)Sample of

Hebrews cemetery tombstone c.) Sample of cliff of the Amal Coast.
http://users/nadjuskaa/Desktop/http://users/nadjuskaa/Desktop/



Three different case studies were investigated: Marly limestone samples from the outer wall of Churchof the Virgin in Martvili in Georgia that showed a peculiar bio deterioration form, Istrian stone samplesfrom Hebrews cemetery tombstone in Venice, and carbonate samples from calcareous cliff of the

Amal Coast.

In this work we report the observations of cross-section by optical microscope (Figure 1) and scanningelectron microscope (SEM) in order to identify the interaction between substrate and microorganisms.Spectra obtained by Raman spectroscopic investigations, carried out in cross-section, were useful todetermine the organic and inorganic compounds used by microorganisms as protective mechanismsagainst stress conditions.The data obtained from the spectra gave rise to identication of molecular bio and geo-marker.

References[1] C. K. Gehrmann, W. E. Krumbein, K. Peterson,International Journal of Mycololgy and Lichenology.

1992,5, 3748.[2] O. Salvadori, Characterisation of endolithic communities of stone monuments and natural outcrops.

In: O. Ciferri, P. Tiano, G. Mastromei, Of Microbes and Art.The Role of Microbial Communities in theDegradation and Protection of Cultural Heritage.2000, pp. 89101.

[3] G. Caneva, M. P. Nugari, O. Salvadori,Plant Biology for Cultural Heritage. Biodeterioration andConservation.The Getty Conservation Institute, Los Angeles, 2009.

[4] A. Danin, G. Caneva,International Biodeterioration & Biodegradation.1990, 26, 397417.[5] V. Lombardozzi, T. Castrignan, M. DAntonio, A. Casanova Municchia, G. Caneva,International

Biodeterioration & Biodegradation.2012, 73, 815.[6] C. Ascaso, J. Wierzchos, J. Delgado Rodrigues, L. Aires-Barros, F. M. A. Henriques, A. E. Charola,

International Zeirschrift fur Bauinstandsetzen. 1998, 4,627640.[7] H. G. M. Edwards, E. M. Newton, D. L. Dickensheets, D. D. Wynn-Williams,Spectrochimica Acta Part A.

2003,59, 22772290.

[8] S. E. J. Villar, H. G. M. Edwards, C. S. Cockell,Analyst.2005,130, 156162.[9] S. E. J. Villar, H. G. M. Edwards,Raman spectroscopy in astrobiology. Anal Bioanal Chem.2006,384(1),

100113.

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FT-Raman analysis of historical cellulosic bres infected by fungi

Katja Kavkler,1*Andrej Demar2

IntroductionHistorical textiles can be degraded by different internal and external factors. Fungi are one of the mostsevere textiles degraders [1], which attack especially pre-degraded materials, since the depolymerisationand changes in inter- as well as intramolecular bonds facilitate access of fungal enzymes to molecules.Textile deterioration has been studied previously with different methods [2,3]. This time we decided toanalyse bio-deteriorated as well as non-affected objects by FT-Raman spectroscopy.

Materials and methodsTextile samplesHistorical samples were obtained from 14 different historical textile objects originating from differenthistorical periods since 16th century. The samples were taken off in the form of pieces of fabrics orsingle threads, from objects, where stains were observed, for which we suspected to be of fungal origin,or where mycelium was observed on the surface of the objects.

FT-RamanThe FT-Raman instrument is a Bruker multiRAM with cryo-cooled Ge detector and a Nd-YAG laser

with a wavelength of 1064 nm with a line width of ~ 5-10 cm-1and a resolution of 4 cm-1. The software

used is OPUS Beta version. The laser intensity has been between 30 and 150 mW. The number of scanshas generally been between 100 and 5000. The surface area of analysis is ~ 20 m in diameter.

Results and discussionOf all the 14 investigated objects, three were made of cotton, two of mixture of ax and hemp and allothers of pure ax. Half of the investigated objects were infected by different fungal strains, amongthem one made of cotton and six made of ax. The infected cotton object was underwear, whereas allother infected objects were painting canvases.

We observed structural properties using FT-Raman spectroscopy, after the dispersive Ramanspectroscopy proved to be long lasting and not always reliable method [2]. However, the FT-Raman

spectroscopic method caused some problems with luminescent background as well. The spectra ofnon-infected cotton specimen, spectra of both samples with mixed bres as well as two spectra of axhad strong background with non-visible or barely visible cellulose bands and their structure could not

be interpreted.

To determine structural changes within cellulose bres we compared spectra from investigated objectswith those from contemporary bres, processed in old fashioned manner, of natural colour and non-sized. Some differences in spectra can be attributed to different growth and processing conditions, butothers are sings for different intensive structural changes.

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1 Restoration Centre, Conservation Centre, Institute for the Protection of Cultural Heritage of Slovenia,

Ljubljana, Slovenia, [email protected] of Textiles, University of Ljubljana, Faculty of Natural Sciences and Engineering,Ljubljana, Slovenia, [email protected]



The inoculated object made of cotton gave spectra with only low background and clear bands. Fromthe spectrum we concluded, that ageing as well as biodeterioration caused decreased crystallinity ofcellulose and its degradation [4], as seen from the decrease of the bands at 380 cm-1, 437 cm-1, 1096 cm-1and 1120 cm-1.

Of the investigated objects made of ax, six were inoculated and four not. In one of the non-inoculatedspectra, obtained from the only object made of ax, which was not painting but an embroideredtablecloth, we could observe opposite changes than usually. The increased bands at 457 cm-1, 520 cm-1and 1120 cm-1are signs of increased crystallinity or more ordered cellulose structure [4-6].

In spectra of two of the inoculated samples no bands could be observed due to strong backgroundemissions, which is probably the consequence of bio-deterioration [5]. In one spectrum only the strongest

bands were visible. Due to deterioration the two bands around 1100 cm-1joined into a broad band withpeak at 1096 cm-1. In three inoculated specimens bands were clearly visible despite the luminescent

background, and the structural changes could be investigated. The decreased bands at 995 cm-1and1480 cm-1 are a sign of deterioration of cellulose in all three investigated spectra, [7] as well as the

decrease of the bands at 1096 cm-1 and 1120 cm-1[5]in two spectra.

From the results of the FT-Raman analysis of museum objects infected by fungi we can conclude that asdoes the dispersive Raman, also the FT-Raman can cause difculties when analysing historical textiles,especially when the bres are severely deteriorated. However, structural changes can be observed inmost of the spectra already after a short acquisition times. In the investigated specimens we observedthat not only biodeterioration, but also other ageing factors can cause changes in cellulose structure.

As seen from our results, the fungi caused more severe decrease in crystallinity than environmentalfactors.

The authors would like to thank Ingalill Nystrom and Department for Conservation of the University

of Gothenburg, Sweden, for giving the possibility to use the FT-Raman in their institution. We wouldalso like to thank Slovene Museum of Christianity, Ptuj Regional Museum and Department for EaselPaintings of the Restoration Centre of the Institute for the Protection of Cultural Heritage of Sloveniafor providing the sampling objects.

References[1] A. Seves, M. Roman, T. Maifreni, S. Sora, O. Ciferri, International Biodeterioration & Biodegradation.

1998, 42, 203.[2] K. Kavkler, A. Demar,Spectrochimica Acta. Part A.2011,78(2),740746.[3] K. Kavkler, N. Gunde-Cimerman, P. Zalar, A. Demar,Polymer degradation and stability.2011,96(4), 574.[4] M. Petrou, H. G. M. Edwards, R. C. Janaway, G. B. Thompson, A. S. Wilson, Analytical and Bioanalytical

Chemistry.2009,395,2131.[5] H. G. M. Edwards, J. M. Chalmers,Raman Spectroscopy in Archaeology and Art History, Royal Society of

Chemistry: Cambridge, Great Britain, 2006, p. 304.[6] H. G. M. Edwards, N. F. Nikhassan, D. W. Farwell, P. Garside, P. Wyeth, J. of Raman spectrosc.2006,37,

1193.[7] H. G. M. Edwards, E. Ellis, D. W. Farwell, R. C. Janaway,J. of Raman Spectrosc.1996,27,663.

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Combined FT-Raman and Fibre-Optic Reectance SpectroscopicCharacterisation of Simulated Medieval Paint Films: a ChemometricStudy of the Effects of Natural and UV-Accelerated Ageing

Anuradha Pallipurath,1Jonathan Skelton,1*Spike Bucklow,2Stephen R. Elliott1

Non-invasive methods for analysing artwork are fast gaining interest due to their facilitating non-destructive and in-situ analyses, without the need for sampling. Raman spectroscopy is one suchtechnique, and has been widely used for this purpose. Despite being a weak phenomenon, Ramanscattering can give a wealth of information about the chemical functional groups that make upchromophores, as well as the crystal structures of pigment molecules, from their atomic-vibrationalspectra. This information can not only be used to characterise the materials in, and hence date, artwork,

but can also be used to detect forgeries.

However, during in-situanalyses of artwork, distinguishable Raman scattering from the pigment canoften be reduced, or even completely masked, by uorescence from the glazing materials or organic

binders used. While a lot of importance has been given to the study of pigments, identifying the organicbinding materials used has never been an easy task. In addition to uorescing at visible wavelengths,most binders also have characteristic vibrational-spectroscopy peaks in the same spectral regions, e.g.corresponding to C-H and carbonyl stretches, making their differentiation challenging. Previously,

we have shown that the use of multiple spectroscopic data sources, e.g. FT-Raman and bre-opticreectance spectra, together with multivariate analysis techniques, not only helps to indentify fat-

based binders, but also proteinacious and polysaccharide-based binders, such as gum Arabic and egg,

which are otherwise difcult to differentiate.[1]

In this work, we have extended these techniques to understand the nature of possible interactionsbetween binders and bound pigments, and to estimate relative concentrations of components in paintlms using FT-Raman spectroscopy. We have also studied naturally and articially (UV) aged samplesto understand how these interactions change with time. In addition, we have developed chemometricmethods to enable computer-assisted analysis of such spectral data from simulated paint samples, witha view to working towards an automated identication of paint-binder materials from spectroscopicdata.

Finally, we have also investigated how several different support materials, viz. glass, canvas and

parchment, the latter two of which, like binding media, are organic materials, inuence the paint lmspectra and hence the results from our analysis techniques.

References[1] A. Pallipurath, J. Skelton, P. Ricciardi, S. Bucklow, S. Elliott,J. of Raman Spectrosc. 2013,44 (6),866874.

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1Department of Chemistry, University of Cambridge, UK, [email protected] Hamilton Kerr Institute, Fitzwilliam Museum, Cambridge, UK



Study of malachite degradation in easel (model) paintings byspectroscopic analysis

Tanja pec,1*Klara Retko,1Polonca Ropret,1,2Janez Bernard3

Malachite, copper(II) carbonate [Cu2+2(CO

3)(OH)

2] is perhaps the oldest green pigment and has been

intensively used in different works of art from Antiquity until late 1800. It has often been proved to bepermanent in oil and tempera paintings, although sometimes brownish hue may appear due to the oildarkening.[1] The present study describes an interaction between pigment and different binders and aneffect of accelerated aging in easel model paintings which were prepared according to the traditionalBaroque recipes.[2]

Before applied on white gesso ground, colour layers containing malachite, mixed with egg temperaand/or oil medium were prepared. As nishing protective layers, egg white and mastics were added onselected areas of the easel painting. The use of different combinations of binders and varnishes enabledan extended study of different inuential factors on pigment degradation. One set of model samples

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1 Research Institute, Conservation Centre, Institute for the Protection of the Cultural heritage ofSlovenia, +386 1 2343118, (tanja.spec, polona.ropret, klara retko)@rescen.si

2 Museum Conservation Institute, Smithsonian Institution, Suitland, MD, USA3 Slovenian National Building and Civil Engineering Institute, +386 1 2804204, [email protected]

Figure 1.

a.)A Photomicrograph of the polished cross-section

and location of spot 2 for Raman analysis.b.)A

Photomicrograph of the polished cross section and location

of spot 3 for Raman analysis. c) Raman spectra of Malachite

(1), Copper oxide (2) and Copper oxalate (3).


28/21728RAA 2013

were exposed to the effects of climate parameters variations, such as temperature, relative humidityand UV-VIS radiation. The other set was left non-aged and it served as the control.Exposure of model easel paintings to environmental parameters in climate chambers was completedafter two months. On both model paintings, colorimetric measurements were made in order todetermine the differences in colour before and after ageing.

Utilizing Micro-Raman spectroscopy, different green areas of each samples cross-section wereanalyzed. Supporting analytical methods, such as SEM (Scanning electron microscopy), FT-IR (Fouriertransform infrared spectroscopy) and XRD (X-ray Diffraction) were employed to obtain additionalinformation on the degradation process of malachite colour layers.The Raman bands of malachite were determined on all control samples, where the bands are in agood agreement with literature data.[3] Beside the green particles of malachite, the black particles werealso detected in all of the samples. Nevertheless, much higher proportion of the latter was observedin the aged samples. Obtained Raman spectra of those particles indicate the presence of a copperoxide. (Figure 1c, Graph 2).[4] In addition, the scanning electron microscopy (SEM) shows the increasedrelative amount of copper on dark particles in respect to green ones. Furthermore, where oil medium

was used as the binder, Raman spectra offered additional results. Beside copper oxide, strong bands

of another compound were recorded at 552, 588, 618 cm-1 (Figure 1b and Figure 1c, Graph 3), whichsuggests the presence of a copper oxalate.[5] The formation of oxalates on easel paintings is more likelyto appear in the presence of biochemical activity of lichens, fungi or bacteria [6], which in our studycan be eliminated, due to the known preparation of the model samples and controlled environmentalconditions in climatic chambers. However, some of the previous studies concluded that decompositionof organic materials, such as proteins, oil, waxes, etc., can also lead towards the formation of oxalicacid [7],which is most likely the reason for the copper oxalate formation found in the present study. Thepresence of oxalate was conrmed also by FT-IR spectroscopy.

References[1] A. Roy (Ed.),Artists Pigments. A handbook of their History and Characteristics,vol. 2 Oxford University

Press: New York, 1993, p. 184.[2] R. Hudoklin, Tehnologije materialov, ki se uporabljajo v slikarstvu,vol. 2, Ljubljana, 1958, p. 121.[3] R. J. H. Clark, P. J. Gibbs,Spectrochim. Acta Part A.1997,53, 2159.[4] L. Debibichi, M. C. Marco de Lucas, J. F. Pierson, P. Kger,J. Phys. Chem. 2012, 116, 10232.[5] K. Castro, A. Sarmiento, I. Martinez-Arkarazo, J. M. Madariaga, L. A. Fernandez, Anal. Chem, 2008,80,

4103.[6] H. G. M Edwards. N. C. Russel, M. R. D Seaward,Spectrochimica Acta Part A.1999,53, 99.[7] N. Mendes, C. Lofrumento, A. Migliori, E. M. Castellucci,J. Raman Spectros.2008,39, 289.

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Portable and laboratory analysis to diagnose the formation ofeforescence on walls and wall paintings of Insula IX, 3 (Pompeii,Italy)

Juan Manuel Madariaga,1*Maite Maguregui,2Silvia Fdez-Ortiz de Vallejuelo,1

Africa Pitarch,1Ulla Knuutinen,3Kepa Castro,1Irantzu Martinez-Arkarazo,1Anastasia Giakoumaki1

Since the time that any archaeological site is brought to light, it suffers deterioration due in part to rain-

fall, humidity, water inltrations, etc., but mainly to environmental stressors. Raman spectroscopy andother analytical techniques, both portable and laboratory, are increasingly used to identify the deteri-oration compounds promoted by the reactivity between stressors (acidic gases, microorganisms, etc.)and original materials that promotes the formation of new compounds (eforescence or crystallizedsalts) like bicarbonates, sulphates and nitrates. In the particular case of the Pompeii site, the impactsdue to the eruption must be added to the others. The APUV expeditions (2010, 2011 and 2012) werefocused on the walls and wall paintings of two houses from Insula IX, 3 (Houses 1,2 and 5,24); somerooms of greater importance are covered with ceilings but the majority of rooms in both houses areexposed to the open air. During the expeditions, the nature of the eforescence in the walls and wallpaintings was evaluated using portable, non-destructive instrumentation. Raman spectroscopy, assist-ed by diffuse reectance infrared spectroscopy (DRIFTS) was used to obtain the molecular composi-

tion and energy-dispersive X-ray uorescence (ED-XRF) for the elemental analysis. Some eforescencesamples were also taken to perform laboratory analysis using the same analytical techniques but alsoDRX and SEM/EDX, as well as some mortar samples, detached from the walls, were taken to performthe soluble salt quantication.Exposed and protected rooms were measured in spring (May 2010) and summer (September 2011 and2012), considering different orientations and the walls affected (and not affected) in its back by rainfallsto observe possible variations in the salts crystallizations. The spring 2010 was with few rainfalls, andlittle amount of eforescence were detected in the walls and practically nothing in the wall paintings ofthe protected rooms. The end of August 2011 was rainy and the walls in the protected rooms, especiallythose oriented in its back to the main rainfalls, were completely wet; some eforescence like crystals

were two to ve millimeters long. The middle of summer 2012 was also rainy, the walls were not wet

when we performed the measurements, but in this case a notable amount of eforescence crystals wereevident even in the wallpaintings of the covered rooms.The CO

2attack on non-protected walls is the greatest decaying phenomena accompanied by rain wash

of the highly soluble metal bicarbonate salts formed after the acid attack (decarbonation of wall paint-ings and plaster layers till observation of the arricciomortar). Any bicarbonate salt was measuredin-situ and only calcium, sodium and potassium carbonate (CaCO

3, Na

2CO

3, K

2CO

3) were identied by

Raman spectroscopy. All of them can be considered original compounds in the mortars; the source forpotassium was found in the own walls, probably coming from the original mortar manufacturing whenusing local potassium-bicarbonate type waters.

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1 Department of Analytical Chemistry, Faculty of Science and Technology, University of the BasqueCountry UPV/EHU, Spain, +34946018298,[email protected]

2 Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country UPVEHU, Spain

3 Department of Art and Culture Studies, University of Jyvskyl, Finland
mailto:[email protected]:[email protected]


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In protected wall paintings and walls (rooms covered by roof) higher sulphur contents were observed(severe sulphation decaying) while a lower amount of sulphur was quantied in exposed walls (partialdissolution of metallic sulphate salts by rain-washing). Apart from gypsum (CaSO

4.2H

2O), thenardite

(Na2SO

4), mirabillite (Na

2SO

4.10H

2O), aphthitalite (K

3Na(SO

4)

2) and syngenite (K

2Ca(SO

4)

2.H

2O) were

detected in areas far from the presence of modern mortars and cements used un past restoration pro-

cesses; sulphates with higher water content were observed in protected rooms where the wall was wet(2011 expedition), i.e., those having its back in front of the main wind (and rain falls) and belonging toother rooms without any roong protection.

Additionally, nitrate salts like lime nitrate (Ca(NO3)

2), niter (KNO

3) and nitrammite (NH

4NO

3) were

detected only in protected rooms due to its high solubility. Especially in the expedition of 2011, nearlypure Raman spectra of niter were collected with the portable instrument, indicating the high concen-tration of this nitrate in the analysed eforescence. But the most surprising result was observed inthe 2012 expedition, where niter was in-situ measured in the white eforescence crystals appearingthrough the pigmented layers in wall paintings of several rooms, all of them having well setting roofs.Chemical modeling and chemometrics were used to explain the results of quantitative concentrationsof ions dissolved from the samples taken to the laboratory. This has resulted in a model that explains

the deterioration process in terms of chemical reactivity, taking into account the orientations of thewalls as well as the covered and not covered situations of the rooms analysed in Insula IX, 3 of thearchaeological city of Pompeii. This model will be presented and discussed.

AcknowledgementsThis work was nancially supported by the projects DEMBUMIES (ref.BIA2011-28148), funded by theSpanish MINECO, and Global Change and Heritage (ref. UFI11-26), funded by the University of theBasque Country (UPV-EHU). The accompanying actions CTQ2010-10810-E (MINECO), AE11-27 (UPV-EHU) and AE12-32 (UPV-EHU) supported the expeditions APUV2010, APUV2011 and APUV2012 re-spectively.

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Decorated plasterwork in the Alhambra investigated by Ramanspectroscopy: eld and laboratory comparative study

Mara Jos Ayora-Caada,1*Ana Domnguez-Vidal,1Mara Jos de la Torre Lpez,2Mara Jos Campos Suol,3

Ramn Rubio Domene4

This work presents the results of the Raman micro-spectroscopic study of decorated plasterworks,

situated on the vaults of the Hall of the Kings in the Lions Palace, at the Alhambra in Granada, Spain.The Alhambra was built and decorated during the Nasrid period in the XIII-XVth centuries and thenadapted during the rst period of Christian domination (XVIth cent). Throughout its history, it hasexperienced many transformations, with the most important and generalized restorations taking placein XIXth century.The decorated plasterwork under study are the mocarabes or stalactites vaults of the Hall of the Kings.These are self-supporting domes built up with gypsum. Vertical gypsum prisms applied one over an -other are joined in multiple different arrays resembling stalactites of a cave. These mocarabes aredecorated with a wide range of colors mainly red, blue, green, golden and black.Our study has been initiated with a totally non-invasive investigation on the eld using a ber-opticportable Raman microspectrometer. The works were conducted on scaffolding platforms at a height of

ca. 12 m above the ground level coinciding with conservation works. The portable Raman microspec -trometer (B&W Tek InnoRam) was equipped with a 785-nm laser and an optical probe head attached toa videomicroscope which was mounted on a tripod motorised in the XYZ axes with remote control.

Good quality Raman spectra were obtained during this survey despite working under non-laboratoryconditions (e.g. dust, scaffolding, vibrations, daylight, temperature differences). The main practicalproblems encountered had been related to lack of space for probe positioning due to the typical stalac-tite like disposition of the mocarabes and vibrations of the scaffolding.

The best results of the eld investigations were obtained from red decorations where cinnabar andminium were clearly identied. The position of cinnabar could indicate that this pigment was originally

used by Nasrid artists although it was also used in restorations. On the contrary, minium seems notto correspond to original decorations. In many areas red colors appeared altered due to degradationproducts some of which were identied in situ (like anglesite and calomel).Furthermore, black decorations showed always the Raman signature of carbon and natural Afghanlapis lazuli was identied in most of the blue decorated motifs. Synthetic ultramarine blue was detect-ed only in one of the vaults revealing a recent restoration. However, we did not succeed in obtaininggood spectra from green and pale blue-greenish decorations. This is because the laser power had to beextremely low to prevent photodecomposition due to the strong absorption of the 785 nm laser light bygreen pigments and the scaffolding vibrations made difcult the use of measurement times longer than

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1 Department of Physical and Analytical Chemistry, University of Jan, Spain,[email protected], [email protected]

2 Department of Geology, University of Jan, Linares, Spain, [email protected], University of Jan, Spain, [email protected] ConservationDepartment, Council of The Alhambra and Generalife, Granada, Spain,[email protected]
mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]


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a few minutes.These eld studies have been complemented with laboratory studies on microsamples. Microsamples

were carefully taken with a scalped taking into account the information provided by the in situ mea-surements. They were studied directly by means of a Renishaw (in Via Reex) Raman microspectrom-eter coupled to a Leika microscope. The best compacted samples were selected to prepare thin cross

sections by embbeding with epoxy resin. With this approach the stratigraphy of the decorations canbe also investigated. In this way, we could conrm our previous hypothesis: in several samples a rstpictorial layer of cinnabar applied over the gypsum substrate appeared covered by a second pictoriallayer of minium. Furthermore, using a 514 nm laser the pale-blue pigment was identied as azurite.Degradation products like calcium oxalates probably formed through microbial degradation of the or-ganic materials employed as binders.In conclusion, the complementary information provided by eld measurements with the portable spec-trometer and laboratory measurements especially on thin cross sections has allowed a good under-standing of the pigments and other materials employed for the decoration of the plasterwork in thisHall of the Alhambra as well as the several degradation phenomena that are taking place.

Figure 1.Detail of the R aman probe head with the

microscope during measure

AcknowledgementsThis work was nanced by the research project CTQ2009-09555 from the Ministry of Science andInnovation. The Council of the Alhambra and Generalife, PAIDI Research Groups FQM 363 and RMN

325 are also acknowledged for supporting this project.

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Multi-technical approach for the study of French Decorative Artsfurniture and luxury objects

Cline Daher,1Ludovic Bellot-Gurlet,2Cline Paris,2 Juliette Langlois,1

Yannick Vandenberghe,1Jean Bleton,3Anne Forray-Carlier,4

Anne-Solenn Le H1 *

During the eighteenth century in Europe, a trend in the furniture eld was to imitate the Asian lac -

quers,[1]known as exceptional for their great aesthetic beauty and gloss (Figure 1), and the delicate andne ornaments. Four brothers, les frres Martin were considered as the most famous painters, gildersand varnishes in Paris, and used to work, followed by their descendents, at the royal court of Louis XV.Their work was dedicated to different types of objects, such as household furniture, small boxes forperfumes or make-up, wooden wall paneling, or even sledges and coaches. Their art of imitating Japa-nese and Chinese lacquers required the development of different painting and varnishing techniques,

based on European familiar material, and became famous for its high and ne quality.

The Martins particularity was to apply a specic varnish Vernis Martin [2]on multilayered paintedbackground, on wooden, papier mch or metallic artifacts. The composition of the varnishes andpaints, the different used materials (resins, pigments, dyes, etc.), and in a larger point of view, the

Martins painting and varnishing techniques, have not been studied yet. These varnishes, or to a largerextent, European lacquers are complex systems made of a colored background, covered with a numberof transparent layers.[3,4]Then, colored or gilded ornaments are applied, representing different charac-ters, owers, or landscapes. The aim of this project was to improve the varnishing techniques knowl-edge in the Decorative Arts eld during the 18th century to enrich the history of art and techniques,and to have a better conservation strategy of such fancy objects.

In order to reveal this unfamiliar complex system and the Martins specic technique, and to charac-terize the employed materials, a combination of analytical techniques was set up. Among these tech-niques, some were non-destructive such as Raman, FT-Raman and infrared in reectance mode,[5]used to identify the varnish composition and the dyes employed for the painted areas directly on the

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1Centre de Recherche et de Restauration des Muses de France (C2RMF), Palais du Louvre Portedes Lions, Paris, France, +33 1 40 20 24 22, [email protected], [email protected]

2 Laboratoire de Dynamique, Interactions et Ractivit (LADIR), UMR7075, UPMC-CNRS, Paris,France

3 Laboratoire d'tudes des Techniques et Instruments d'Analyse Molculaire (LETIAM), IUT d'Orsay,Orsay, France

4Muse des Arts Dcoratifs, Les Arts Dcoratifs, Paris, France

Figure 1. Photography of a French imitation

of Japanese artwork. Inv57965, Muse des Arts

Dcoratifs, Paris.


34/21734RAA 2013

object, or on micro-samples taken from lacunar areas of the artifacts. Other methods were employed tocomplete the organic analyses (GC/MS, py-GC/MS) or to characterize the mineral compounds (SEM,micro-diffraction).

The presented results are mainly the vibrational analyses ones, on which specic spectral treatments

[6]were applied in order to extract detailed information and a better molecular identication thanksto these vibrational signatures. A synthetic overview of the whole obtained data is given, showing thesingularity of these complex European preparations not or poorly studied.

AcknowledgementsThe authors would like to thanks the different museums which collaborated to this project, givingaccess to all the studied objects: muse des Arts Dcoratifs (Paris), muse du Louvre (Paris), and LeChteau de Versailles. This work has been nancially supported by the foundation Sciences du Patri-moine and Labex Patrima.

References

[1] A.-S. Le H, M. Regert, O. Marescot, O., C. Duhamel, J. Langlois, T. Miyakoshi, C. Genty, M. Sablier,Anal.Chim. Acta.2012,710, 9.

[2] J. F. Watin,Lart de faire ou demployer les vernis, ou lart du vernisseur, Quillau, Paris, 1772.[3]A.-S. Le H, E. Ravaud, J. Langlois, A. Mathieu-Daud, E. Laval, A. Jacquin, I. Chochod, M. Bgu, J.

Mertens, M.-L. Deschamps, A. Forray-Carlier,ICOM Committe for Conservation: 16th Triennial Meeting,Lisbon, Portugal,19-23 September, 2011,Preprints, electronic format 2011(CD-ROM).

[4]A. Rizzo,Anal. Bioanal. Chem. 2011,392, 47.[5]W. Vetter and M. Schreiner, e-Preservation Science. 2011, 8, 10.[6] C. Daher, PhD thesis, Universit Pierre et Marie Curie (UPMC), 2012, available online: http://tel.ar-

chives-ouvertes.fr/tel-00742851/

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Deterioration of lead based pigments on a fresco: a micro-Ramaninvestigation

Ilaria Costantini,1Antonella Casoli,1 Daniele Pontiroli,2Danilo Bersani,2Pier Paolo Lottici 2*

Micro-Raman spectroscopy analyses were carried out on some pictorial fragments taken from a portionof the fresco in the Chapel of St. Stephen, situated in Montani (BZ), Val Venosta, Italy, and paintedaround 1430. Within this building, especially on the apse and on the vault, an alteration of lead basedpigments is clearly visible, as a dark coating. The lead pigment was presumably mainly white lead, usedto create highlights and light and dark effects. Samples were taken from altered blackened areas and

from areas cleaned according to the traditional method of conversion of white lead, using a solutionof acetic acid and hydrogen peroxide in cellulose pulp. Thecleaned samples appear in their originalcolors, yellow and green. The samples taken from cleaned areas show characteristic spectra of lead-tin yellow pigments, both type I and type II, identiedpredominantly from green samples.Goethite,hematite, celadonite green earth, and lapis lazulihave also been found.The Raman spectra have been taken at very low (< 0.1 mW) laserpower due to the complex behaviour of lead oxides for photo-thermal effects induced by the laser excitation (here 632.8 nm).[1]The micro-Raman spectra from blackened degraded samplesgive no evidence of white lead but show always a structured wide

band centered at about 515-520 cm-1which can be attributed tothe presence of plattnerite (PbO

2), well known alteration product

of lead based pigments, especially in presence of moisture andin strongly alkaline environment. The Raman spectra are nearlyinsensitive of the laser power and very often show PbO (litharge/massicot) features of varying intensities. Other features at about230 cm-1and 600 cm-1 cannot be attributed to lead oxide phases,litharge or massicot (Figure 1). On the other hand, starting fromsynthetic plattnerite, lead oxides (red lead Pb

3O

4, litharge and

massicot) are obtained at increasing laser power (Figure 1).The nature of the dark degradation material is discussed on the

basis of Raman and XRD results and on degradation tests onwhite lead, with different binders.

References[1] L. Burgio, R. J. H. Clark, S. Firth,Analyst, 2001,126, 222227.

Figure 1. Raman spectrum of the black

degradation material a.) compared with

that of plattnerite b.). c.) and d.) are Raman

spectra (massicot and litharge, respectively)

obtained by laser photo-degradation of

plattnerite.

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1 Chemistry Department, University of Parma, Italy,+39 0521 905425, [email protected]

2Physics and Earth Sciences Department, University of Parma, Italy,+39 0521905238, [email protected]


36/21736RAA 2013

Investigation of colour layers in easel (model) paintings inuencedby different ageing process

Klara Retko,1*Tanja pec,1Polonca Ropret,2

Investigation of deterioration and material degradation on works of art has a great impact in designingbetter conservation and preservation procedures. Colour layers stability depends to a great extent onthe individual stability of a pigment and binder, and possible pigment-binder interactions. Inuentialfactors such us UV-VIS radiation, pollutants exposure, and humidity and temperature oscillation mayalso accelerate degradation processes.In this study, changes of physical and chemical properties of different colour layers as a consequence

of degradation are presented. For that purpose several easel (model paintings), containing differentcolour layers were prepared in which all materials selected for the preparation of model samples corre-sponded to the materials used in the Baroque period.[1]Therefore pigments such as lead white, lead tin

yellow (type I), prussian blue, smalt, azurite and vermilion were employed. Each pigment was mixedwith egg tempera or oil medium and applied on a gesso ground.Model samples were then exposed to articial accelerated ageing process for a period of two months,using well-controlled climatic chambers. One set of model easel paintings was exposed in the climaticchamber where oscillations of temperature and relative humidity were performed, while the other setof samples was exposed to the UV-VIS radiation. The last set of model samples was left non-aged andserved as control.

Utilizing Micro-Raman spectroscopy all colourlayers were examined. The main differences inRaman spectra of aged and non-aged samplesthat indicate possible degradation process were

observed in azurite and lead white containingcolour layers.

After completed accelerated aging process ofblue azurite colour layers, greenish hue has

been observed. According to literature data, conversion of blue pigment azurite (Cu3(CO

3)

2(OH)

2) to the

green pigment malachite (Cu2(CO

3)

2(OH)

2) is possible, although mechanism is not well understood.[2]

The Raman bands at ~ 153, 180, 220, 269, 354, 432, 1055, 1091 and 1491 cm -1revealed the presenceof malachite[3](Figure 1), interestingly, only in colour layers prepared in oil medium, and after bothexposures (UV-VIS and T, RH). It is possible that the presence of malachite stems from azurite conver-

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1 Research Institute, Conservation Centre, Institute for the Protection of Cultural Heritage ofSlovenia, Ljubljana, Slovenia, +386 1 2343118, [email protected], [email protected]

2 Museum Conservation Institute, Smithsonian Institution, Suitland, MD, USA

Figure 1. Raman spectra of non-aged azurite colour layer (AZ_

B2_REF) and azur ite colour layers after T,RH (AZ_B2_T,RH)

and UV-VIS exposure (AZ_B2_UV-VIS). In all presented

samples, linseed oil (B2) was selected as the binder.



sion, which appears to be less stable in the medium with higher amount of fatty acids. In cases, whenazurite was mixed with lead tin yellow and lead white, it showed a lower stability in the egg temperaafter exposed to UV-VIS radiation. To acquire additional knowledge on mechanism of reactions furtherresearch is necessary.In lead white colour layers, which were prepared with both binders and exposed to UV-VIS radiation

changes in Raman spectra were observed The additional band at 967cm-1(Figure 2) can be assigned to(SO

42-). It is possible that the lead white interacted with a sulphate containing compound.[4]

While the easel painting have not been exposed to air pollutants, such as SOx, which could initiatethe formation of sulphates, the source of sulphates is possibly contributed to gypsum (CaSO

42H

2O),

present in the ground layer. Interestingly, the effect was observed only after UV-VIS exposure and notunder humid conditions. However, additional research needs to be carried out.

References[1] R. Hudoklin, Tehnologije materialov, ki se uporabljajo v slikarstvu,vol. 2. Ljubljana, 1958, p. 121.[2] A. Lluveras, S. Boularand, A. Andreotti, M. Vendrell-Saz,Applied Physics A.2010, 99, 363.[3] R. J. H. Clark, P. J. Gibbs,Spectrochimica Acta Part A.1997,53, 2159.[4] E. Kotulanov , P. Bezdika, D. Hradil, J. Hradilov, S. varcov, T. Grygar,J. Cult. Her.2009. 10, 367.

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Figure 2. Raman spectra of non aged lead white colour

layers prepared with egg yolk (LW_B1_REF) and linseed oil

(LW_B2_REF) and after UV-VIS exposure (LW_B1_UV-VIS,LW_B2_UV-VIS).


38/21738RAA 2013

Identication of copper azelate in 19thcentury Portuguese oilpaintings: Characterisation of metal soaps by Raman Spectroscopy

Vanessa Otero,1,2 Diogo Sanches,1, 2Cristina Montagner,1, 2Mrcia Vilarigues,1, 3Leslie Carlyle,1, 2Maria J. Melo1, 2*

Several 19th century oil paintings by the artist Toms da Anunciao(1821-1879) who is considereda prominent gure of Portuguese romanticism were studied. The identication of the green pigmentused in the trees and foliage was not straightforward. The presence of copper in cross-sections wasconrmed by micro-Energy Dispersive X-ray Fluorescence (-EDXRF) and Scanning Electron Micros-copy coupled with an Energy Dispersive X-ray Spectrometer (SEM-EDS). The green particles were then

characterised by micro-Fourier Transform Infrared Spectroscopy (-FTIR) and Raman Microscopy(-Raman). The infrared ngerprint does not match a copper resinate, but it was possible to detect a

band at 1586 cm-1attributed to the asymmetric COO -stretching of copper carboxylates [1,2].The detec-tion of these compounds was also conrmed by -Raman through the identication of bands at 1440cm-1and 1296 cm-1assigned to CH

2bending. This indicates a reaction between the copper pigment with

the surrounding oil binding media [2,3].

Based on these ndings, it was decided to test a new set of metal soaps synthesised in the laboratory.The synthesis method was adapted from Robinet and Mazzeo [1, 4]. Metal salts of lead, zinc, calcium,cadmium, copper and manganeseIIwere used and the carboxylic acids chosen were palmitic, stearic,azelaic and oleic acids. Characterisation was performed by -FTIR, -Raman and X-ray Diffraction

(XRD) and it is anticipated that these results will be of great value for in situdetection of metal soapsby -Raman.

The distinction between the saturated carboxylates, copperpalmitate and stearate, is not straightforward. The applica-tion of a chemometrics approach based on -Raman data, forthe discrimination of the type of carboxylate, was tested and

will be discussed.In contrast, copper azelate and oleate show distinct spectra

by -Raman as well as by -FTIR. Copper azelate shows a dif-ferent Raman CH

2bending prole and different characteris-

tic bands for C-C stretching and bending. As may be seen ingure 2, the green degradation product detected on Tomsda Anunciao oil paintings matches the copper azelate-Raman spectrum. Its identication was also conrmed by-FTIR on a very small green micro-sample, free from lead

white. It was possible to identify both the asymmetric andsymmetric COO-stretching of copper azelate at 1586 cm-1and

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1Departamento de Conservao e Restauro, Faculdade de Cincias e Tecnologia, Universidade Novade Lisboa, Portugal,[email protected]

2REQUIMTE-CQFB, Faculdade de Cincias e Tecnologia, Universidade Nova de Lisboa, Portugal3VICARTE, Faculdade de Cincias e Tecnologia, Universidade Nova de Lisboa, Portugal

Figure 1.Oil painting on canvas entitledPaisagem

e Animais(1851) from Toms da Anunciao.
http://c/Users/Diogo%20Sanches/AppData/Local/Temp/[email protected]://c/Users/Diogo%20Sanches/AppData/Local/Temp/[email protected]



1417 cm-1, respectively.

AcknowledgementsThis work has been nancially supported by national funds through FCT- Fundao para a Cincia ea Tecnologia under the project PTDC/EAT-EAT/113612/2009. We also thank FCT-MCTES for Vanessa

Oteros PhD grant SFRH/BD/74574/2010, Cristina Montagners PhD grant SFRH/BD/66488/2009 andDiogo Sanchess PhD grant, SFRH / BD / 65690 / 2009. We would also like to thank the curator of TheMuseu Nacional de Arte Contempornea Museu do Chiado, Maria de Aires, for her collaboration.

References[1] L. Robinet, M. Corbeil,Sudies in Conservation. 2003, 48, 2340.[2] M. Gunn, G. Chottard, E. Rivire, J. Girerd, J. Chottard,J.Studies in Conservation. 2002, 47, 1223.[3] J. J. Boon, F. Hoogland, K. Keune,AIC paintings specialty group postprints: papers presented at the 34th

annual meeting of the AIC of Historic & Artistic Works providence,Rhode Island, 1619 June, 2006. AIC:H. M. Parkin, Washington, 2007, pp. 1623.

[4] R. Mazzeo, S. Prati, M. Quaranta, E. Joseph, E. Kendix, M. Galeotti, Anal. Bional. Chem.2008, 392, 6576.

Figure 2.Raman spectra of a.)green area of a cross-section taken

fromPaisagem e Animaisoil painting of Toms da Anunciao,

b.)copper azelate and c.)copper palmitate.

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40/21740RAA 2013

Raman study of pigment degradation due to acetic acid vapours

Alessia Coccato,1*Nathalie De Laet,2Sylvia Lycke,1,2Jolien Van Pevenage,2Luc Moens,2Peter Vandenabeele1

The conservation of works of art that consist of different materials is complicated as the componentmaterials are not equally sensitive to the same environmental conditions. Humidity, light exposureand temperature are known to be dangerous to cultural heritage objects, favouring their degradationthrough physical, chemical and biological processes. These factors can be easily controlled, especially

when the work of art is placed at display in a museum, with limited air circulation, controlled humidity,and temperature.Nevertheless, display cases with wooden parts may cause further damage to their content, becauseof the release of acetic and formic acid.[1]This evidence has been highlighted by many studies,[2-4]and

proved to be itself sensitive to humidity and temperature conditions.For conservative purposes, it is necessary to study also the contribution of acid organic pollutants tothe degradation of the materials present in a work of art. Studies are currently performed on pigments,

varnishes, leather, parchment, paper and textiles, in the frame of the European FP-7 project MEMORI.Our research is focused on pigment degradation and on the development of a passive air samplercoupled to a dosimeter reader, which is the MEMORI-dosimeter, to monitor the combined effects of allthe conditions to which the art object is exposed (climate, organic and inorganic vapours).The pigment selected for this study are malachite (Cu

2(CO

3)(OH)

2), lead white (Pb

2(CO

3)(OH)

2), red lead

(Pb3O

4), lead-tin yellow type I (Pb

2SnO

4) and pigment orange 36 (C

17H

13ClN

6O

5). Different acetic acid

atmospheres were produced to simulate the release of organic pollutants from wood in closed cases.Five samples of each pigment were kept in the closed vessels and monitored over 5 weeks.

The evaluation of the effects of acetic acid were checked both as a change in colour, and with Ramanspectroscopy. Samples were analysed with a Kaiser Hololab 500R spectrometer (=785 nm) or aBruker Senterra spectrometer (=532 nm). To take sample inhomogeneity into account, 100 spectra

were recorded for each sample, and the results were averaged. Here we present some results for lead-tin yellow (type I). The spectrum of the original pigment is in good agreement with literature (topspectra in Figure 1 and Figure 2) is in good agreement with literature, [5]while it is possible to noticethe appearance of new bands (652, 924, 1337, 1422, 2940 cm-1) and sometimes the decrease in intensityof some bands (452 cm-1) in relation with increasing dose (time x concentration), as can be seen inFigure 1. No shifts in the band positions were noticed. The newly formed bands can be ascribed to theformation of acetate salts of lead (II). It seems that acetic acid does not affect the (Sn-O) vibration at194 cm-1, while the (Pb-O) stretching band at 452 cm-1decreases in intensity, suggesting the formation

of lead acetate and tin dioxide. The white colour of lead acetate is responsible for the lightening ofthe yellow tint. The studied pigments showed a different sensitivity towards the aggressive acetic acidatmosphere, some of them being reactive but showing no change in colour (lead acetate is white, as

well as basic lead carbonate[6]), some showing strong colour changes (lead-tin yellow type I becomespaler,[7]malachite turns to a bluish-green shade because of the formation of verdigris,[7]red lead darkensprobably in relation to the formation of the black lead(IV) oxide plattnerite [8]), nally pigment orange36 showed no changes in colour nor in the vibrational spectrum.Raman spectroscopy demonstrated once more its effectiveness in the characterization of pigmentsand their degradation products, in this case in combination with digital photography and RGBmeasurements.

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1 Department of Archaeology, Ghent University, Belgium,[email protected], [email protected] Department of Analytical Chemistry, Ghent University, Belgium
mailto:[email protected]:[email protected]:[email protected]:[email protected]



AcknowledgementsThe authors wish to acknowledge the MEMORI project for their nancial support and for theinteresting discussions with the colleagues. The MEMORI, Measurement, Effect Assessment andMitigation of Pollutant Impact on Movable Cultural Assets. Innovative Research for Market Transfer,project is supported through the 7 Framework Programme of the European Commission (http://www.

memori-project.eu/memori.html).

References[1] W. Hopwood, T. Padeld, D. Erhardt,Science and Technology in the Service of Conservation. 1982, 24

27.[2] T. Baird, N. H. Tennent,Studies in Conservation.1985,30, 7385.

[3] C. Laine,Structures of Hemicelluloses and Pectins in Wood and Pulp. University of Technology: Helsinki,Espoo, Finland,2005.

[4] L. T. Gibson,Corrosion Science. 2010,52, 172178.[5] I. M. Bell, R. J. H. Clark, P. J. Gibbs,Spectrochimica Acta Part A. 1997,53(12), 21592179.[6] J. E. Svensson, A. Niklasson, L.G. Johansson, Corrosion Science.2008, 50, 30313037.[7] G. Calvarin, N. Q. Dao, J. P. Vigouroux, E. Husson,Spectrochimica Acta Part A. 1982, 38, 393398.[8] D. A. Scott, T. D. Chaplin, R. J. H. Clark,J. of Raman Spectroscopy.2006,37, 223229.[9] L. Burgio, R. J. H. Clark, S. Firth. The Analyst.2001, 126, 222227.

Figure 1. Left: Effect of time on lead tin yellow type I exposed to 33% acetic acid vapours. From top to bottom: pure

pigment, after one, three and ve weeks of exposure. Right:Effect of increasing concentration of acetic acid on lead tin

yellow type I, after four weeks of exposure. From top to bottom: pure pigment, 9%, 20% and 33% acetic acid atmosphere

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42/21742RAA 2013

Investigating the sources of degradation in corroded lead sculpturesfrom Oratory Museum (Museu do Oratrio), Brazil

Thiago Sevilhano Puglieri,1Dalva Lcia Arajo de Faria,1*Luiz Antnio Cruz Souza2

The presence of acetic and formic acids and formaldehyde, combined with inadequate environmentalconditions, as high relative humidity (RH) and temperature, constitute a very threatening scenario forthe integrity of materials such as metals [1-3]. Wood is a common source of such volatile organic com-pounds and its use in showcases should be avoided. However, Pb sculptures from Oratory Museum(Museu do Oratrio) at Ouro Preto, in the Brazilian state of Minas Gerais, exposed inside glass show-

cases presented an increasing degradation (Figure 1) and the corrosion sources were to be identied tostop further damage.

Small fragments of the corrosion products, a whitish hair-like material, were collected and analyzed byRaman microscopy, stereomicroscopy, SEM-EDX, FTIR and XRD. Raman spectroscopy was also usedto test possible sources of pollutants.

Stereomicroscopy conrmed the formation of crystals, excluding the possibility of afungiattach, whileSEM-EDX also revealed the presence of Pb, C and O. XRD detected basic lead carbo

Raman Spectroscopy Applied to the Study Cretaceus Fossils

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