Identification of organic materials in icons of the Cretan School of iconography

The Cretan School of iconography is the last great flowering of the traditional Byzantine painting manner, which is however influenced by different schools and western art. Despite their historical significance, icons of the Cretan School have been rarely studied through modern chemical techniques and therefore very few information is available on the materials used by the Cretan painters. In the present investigation, the organic materials contained in several icons of the Cretan School of Iconography from the collection of the Benaki Museum, Athens, Greece, are analyzed and identified by High Performance Liquid Chromatography coupled to a Diode Array Detector (HPLC-DAD) and Gas Chromatography with Mass Spectrometry (GC-MS). The HPLC-DAD results provide support to a recently published report which showed that kermes used in Cretan icons of 15th century and early 16th century was replaced by cochineal which was used in icons dated after early 16th century. This trend is known for western art and it is now proved for Cretan icons, showing thus the influence of the Cretan painters by other European painting schools. Other dyes detected in the historical samples, extracted from Cretan icons are madder (possibly Rubia tinctorum L, according to HPLC profiles) and indigoid dyes. Oils, such as linseed and walnut oil, are identified in samples extracted from the seven icons tested by GC-MS. Egg yolk is identified in the extract of only one icon and animal glue, originated most likely from the gesso ground, is found in six samples. Other organic materials detected by GC-MS were wax, as well as synthetic resins, applied during conservation treatments. (C) 2010 Elsevier Ltd. All rights reserved.