ČERVENÉ ORGANICKÉ PIGMENTY A MOŽNOSTI JEJICH IDENTIFIKACE V MALBĚ.

Šefců, Radka; Antušková, Václava; Havlová, Markéta; Kšírová, Petra

Identification of art materials in artworks is essential for both understanding the context of the origin of the work of art and for understanding historical technological procedures, which are important for recognizing the time of creation of the work itself and, eventually, even for determination of its authenticity. This article deals with identification of mainly red synthetic pigments via three different methods – infrared and Raman spectroscopy and high-performance liquid chromatography with diode array and fluorescence detectors. Spectra with multiple intense absorption bands were obtained on standards via infrared spectroscopy. However, measurements on samples were affected by the presence of other components of the heterogeneous paint layered system making the identification of the pigment complicated or even impossible. Raman spectroscopy proved to be suitable for the analysis of most synthetic pigments. On the other hand, identification of red lakes precipitated from natural dyes is not possible due to the fluorescence. Liquid chromatography plays an important role in the identification of organic pigments as it can detect natural colorants as well as most synthetic pigments. Low concentration of the analyzed pigment sometimes proved to be a limiting factor. The main advantage of this method is the possibility to identify individual components in multicomponent organic pigment mixtures. These three methods of pigment identification were tested on samples taken from works of art dating from the 19th and 20th centuries. Synthetic alizarin and natural madder lake were successfully distinguished and red colorants based on naphthol were identified.

PROVENANCE of art; HIGH performance liquid chromatography; RAMAN spectroscopy; ART materials; INFRARED spectroscopy

Fórum pro Konzervátory-Restaurátory, 2024, p27

1805-0050

Academic Journal

10.61574/FKR.2024.1.027