# Research on the Organic Binders in Archaeological Wall Paintings
## 4 Exploring Research Results
### Invasive Techniques
A study on the wall paintings of the Abu El Leaf Monastery, also known as Deir Abu Lifa, is considered one of the most important and famous monasteries in Fayoum Oasis, Egypt, was carried out. Arabic Gum as organic binding medium suggests that tempera technique was used in The Abu El Leaf Monastery in Fayoum Oases [70]. A study conducted by [PERSON] et al. (2019) considered samples of Maya wall paintings of ten archaeological sites situated in Campeche and Yucatan regions. This work, carried out by GC-MS, defined the presence, in significant amounts, of a series of monosaccharides, being glucose and mannose between the most abundantly found. This detection opens the question of the deliberate employ of these organic polymers as additives to improve workability and mechanical properties in the preparation layer mortar and to confer cohesion to the pigments in the paint layer. Unfortunately, the small sample size and sensitivity of the analytical technique prevent the identification of the vegetal gum used. Identification is further complicated if it is assumed that the samples from wall paintings are composed of mixtures of polysaccharide materials from bark and various parts of plants, which can be easily extracted in water [71]. [PERSON] et al. conducted an extensive study on the pictorial technique used in the Etruscan tomb \"Tomba della Quadriga Infernale\" in Sarteano (Siena, Italy). The numerous pigments used have been identified and the presence of egg has been found, by GC-MS, as a binder for the drafting of polychromy [72]. Still talking about Etruscan painting mural, a study in ancient city of Caere near Rome, Italy, identified the limited pigments used and did not find the presence of an organic binder, suggesting a lime water binder [73]. A study of [PERSON] et al. has employed spectroscopic, techniques and GC coupled to flame-ionization detector to study binders of a mural painting fragment from Liternum (Italy) archaeological excavation [74]. The results obtained were compared with those obtained from the examination of collected samples in Pompeii from \"Imperial Villa, Insula Occidentalis\" suggesting that in both cases tempera painting with binders of animal origin had been used [75; 76]. A paper by [PERSON] et al. (2012) considered Pompeii wall paintings samples of different age. FT-IR spectra obtained from the Pompeii samples of different age showed almost overlapping patterns with very few differences thus suggesting a quite similar chemical composition among the samples, therefore not showing variations in the historical periods considered [77]. Several other studies have been conducted by [PERSON] et al. on Pompeian wall paintings. The authors, after extraction of the pulverized paint powder with polar and nonpolar solvents, used liquid chromatography, gas chromatography with flame ionization detection, and gas chromatography-mass spectrometry to estimate the free amino acids, and fatty acids profiles [74; 78]. Research carried out by [PERSON] et al. has employed several analytical techniques for study Roman mural paintings from House of the Golden Bracelet in Pompeii and the Villa of Papyri in Herculaneum. Organic binders have been sought using infrared spectroscopy and Py-GC-MS. The results of FTIR spectroscopy indicate the presence of some glue or gum compound type. The completion of the study showed vegetable wax or beeswax and some types of protein and gum compounds, thus highlighting the presence of dry paint [79]. Research on Insula del Centenario in Pompeii was conducted. The objectives of this study are two: to locate the presence of protein and lipid materials to spread pigments and identify organic matter in painting materials due to previous restoration work. Small amounts of sample (0.1-0.8 mg) were taken by scraping the surfaces of the paintings with a bistoury (Figure 1).