ORIGINAL PAPER The contribution of gas chromatography to the resynthesis of the post-Byzantine artist’ s technique Eleni Kouloumpi & Graham Lawson & Vassilios Pavlidis Received: 10 April 2006 / Revised: 16 June 2006 / Accepted: 25 August 2006 / Published online: 7 November 2006 # Springer-Verlag 2006 Abstract Gas chromatographic analysis of ethyl chloro- formate derivatives of samples taken from the paint layers of post-Byzantine panel paintings permitted the successful characterisation of the different binding media used in them. This paper describes an analytical study of various post-Byzantine binding media such as egg yolk and egg/oil emulsion, using gas chromatography. The characterisation of these icons’ binding media is an important task, as it contributes to our understanding of and the reconstruction of the post-Byzantine artists’ palette. It also enables us to investigate the validity of our assumptions about the influences of Venetian style on Greek icon painting techniques from the sixteenth to the early nineteenth century, which up to now have been based on information in artists’ handbooks. The methodology involves two experimental steps: (1) hydrolysis of the proteins and triglycerides in the binding media to obtain free amino acids and fatty acids, and (2) the formation of ethyl chloroformate derivatives via derivatization with ethyl chloroformate (ECF). This methodology is of considerable interest, since it permits the identifcation of the nature of the proteinaceous binders used in these works through the simultaneous derivatization and determination of amino acids and fatty acids. Advantages of this methodology include the small quantity of sample required and the minimum preparation time involved. The proteinaceous media can be determined based on the ratios of seven stable amino acids, while the type of emulsions and drying oils used can be determined from the fatty acid ratio. Keywords Post-Byzantine icon paintings . Binding media identification . Egg tempera . Ethyl chloroformate derivatives . Gas chromatography Introduction The techniques and materials used by artists are directly associated with the geographical, social and time frames in which they lived and created. The end of the Byzantine era, one of the most important historical and artistic times in human history, was the beginning of a transitional period during which Greek iconography changed from the religious to the secular [1–4]. This change took place through a series of cultural interchanges with Western Europe. Along with the change in style, the technique used changed as well; egg tempera evolved to oil painting, through a phase where an emulsion of egg yolk and a drying oil was used. The basic structure of a panel painting [5] comprises the substrate, the gesso ground, the paint layers, and the varnish. The paint layers consist of inorganic or organic Anal Bioanal Chem (2007) 387:803–812 DOI 10.1007/s00216-006-0802-x Electronic supplementary material Supplementary material is available in the online version of this article at http://dx.doi.org/ 10.1007/s00216-006-0802-x and is accessible for authorized users. E. Kouloumpi (*) Conservation Department, National Gallery–Alexandros Soutzos Museum, 1 Michalacopoulou Street, 11601 Athens, Greece e-mail: elenikouloumpi@nationalgallery.gr G. Lawson Faculty of Health and Life Sciences, De Montfort University, Hawthorn Building, Leicester, LE1 7RH, UK e-mail: glawson@dmu.ac.uk V. Pavlidis School of Allied Health Sciences, De Montfort University, Hawthorn Building, Leicester, LE1 7RH, UK e-mail: bpav@dmu.ac.uk