Analytical study of representative art objects of the Mediterranean cultural heritage as far as the identification and characterization of organic colouring materials and the technology of their application is concerned.

The artworks and artefacts – textiles, manuscripts and icons – will be selected by all partners according to historic and technical criteria assuring the representation of the main phases of Mediterranean civilizations. They will have clear provenance and exact dating, and will be inter-comparable as to the various applications of the colouring material. They will represent all major types of organic dyes as to the plant or animal used and the hue achieved. The artworks and artefacts thus selected will be chemically analysed by generally accepted methodologies for organic dye identification such as TLC, UV-Vis Derivative Spectrophotometer, HPLC-DAD-MS, FTIR (Attenuated Total Reflection FT-IR-technique and FT-IR Microscopy), Raman Spectrometry and Pyrolysis Capillary Gas Chromatography with Mass Spectrometry. The state of artworks will be determined by several microscopic techniques, including optical microscopy, TEM and SEM.

In the context of art diagnosis the term “identification” is not restricted to a simple chemical meaning, and can embrace such information as provenance of the materials used, technology and concrete techniques of their application, history and present condition of the object. This information may need the identification of other (contaminants) components of the dye. Within the framework of dyeing technology investigation, other organic and inorganic substances – such as binders and mordant cations – will be considered by means of GC-MS, FTIR, Raman spectroscopy and Atomic Absorption Spectrometer. The information obtained by the analytical study of art objects will lead, in addition to the clarification of the colouring technology used in art objects of the Mediterranean area, to the formulation of appropriate recommendations for optimum conservation strategies for the tested objects.

Sub-objective 1-1: An overall collection of historical data regarding natural dyestuff sources such as plants, insects and mollusks typical for the Mediterranean area and a ncient recipes on lake – organic pigments production, including dyestuff extraction of the source and lake preparation, will be beneficial for accurate dyestuff identification and characterization and necessary for objective 2. Encyclopedic essays or practical manuals will be examined. Originating from ancient Greek and Roman, medieval Arabic, Byzantine and South European, as well as traditional and modern Mediterranean sources, the recipe collection will cover more than two millennia of technical literature on natural colouring dyes. For this task already available, preliminary results issue of cooperative bi or tri-lateral initiatives of the partners in the framework of previous, thematically

related initiatives will be integrated [ Natural Colouring Lacs in Europe”, Culture 2000 Framework Programme (2000-2001)].

Sub-objective 1-2: To perform an accurate and safe natural (organic) dyestuff identification by HPLC-DAD-MS the availability of corresponding standards, i.e. active colouring ingredients of the dyestuffs, is necessary (especially when the MS is not in use). The lack of standards in this area of analytical chemistry is well known and it is probably one of the main limitations, observed in the current literature. Within the framework of the project several standards, not available currently in the market, will be synthesized, based on routes that have been developed by partners of the consortium and the corresponding literature.

Sub-objective 1-3: Successful analysis of “real” samples, extracted from art objects, requires the development of an appropriate HPLC method, using primarily reference dyestuff samples. HPLC-DAD has been successfully used for many years for the identification of natural dyestuffs and consequently several methods can be found in the literature. Coupling HPLC-DAD with MS provides enhanced analytical capabilities. However, the sophisticated HPLC-DAD-MS technique requires the development of more elaborate analytical techniques that will exploit the advantages of both detectors simultaneously, the DAD and the MS. The latter can be considered as being at a primary stage for natural dyestuff analysis. Apart from the HPLC, the main analytical instrument, corresponding methodologies will be developed for the rest on the instrumentation, participated in the chemical characterization of the artefacts .

Sub-objective 1-4: Extraction and preparation methods of organic colourants might affect the subsequent chemical analysis. Consequently, developing an extraction and sample preparation method, using primarily reference samples, will be an important sub-objective of this project.

Chapter 7.6, associated with wokpackage description, shows how (the way) objective 1 and the relative sub-objectives 1-1, 1-2, 1-3 and 1-4 will be achieved. Below it is described which objective is related to which workpackage and therefore to which corresponding milestones, indicated in chapter 7.6. This interrelation shows when (the time) sub-objectives are expected to be achieved. Specifically, sub-objective 1-1 is expected to be achieved upon completion of WP 2, while sub-objective 1-2 will be the target of WP 3. The major goals set in sub-objective 1-3 will be accomplished in WP 4 at which art objects will be analyzed with respect to their colouring content. Minor optimization of the analytical procedures, however, might be achieved within the framework of WP 5 and WP 6. The latter will mainly deal with sub-objective 1-4, achieved by the end of WP 6. Form the above it is obvious that objective 1 will start at the first month of the project (WP 2 is initiated immediately after kick-off meeting) and will be accomplished upon WP 4 completion. However, minor aspects relating to the optimization of the dyestuff analytical procedures might be clarified at WP 5 and WP 6.