This work is focused on the study of triterpene part of three natural plant resins commercially available, olibanum(frankincense), dammar and mastic, by various analytical techniques (FTIR, HPLC / UV, HPLC / UV / Fluorimetry and GC -MS). Afluorimetric study was conducted on these three resins via grafting reaction of a fluorescent marker (dansyl chloride), whichallowed to detected triterpene molecules by fluorimetry, decreasing their detection threshold and to obtain a specificfluorimetric fingerprint for each studied resin. This protocol has been successfully applied on an archaeological sample (G14)and the resinous material has been identified (the olibanum resin, the species B. frereana). A triterpenic fraction was extractedby various extraction procedure (reflux, Soxhlet and ultrasounds) using three different solvents (methanol, n-hexane, and dlimonene)in order to determine the optimal conditions for the extraction and identification of triterpenic molecules by HPLC /UV. Two reversed phase columns were tested in this work: a classical column RP-18 (Merck) and column «core-shell» Kinetex(Phenomenex) to try to optimize the analysis conditions. Kinetex column has allowed a reduction of analysis time to 73% foranalyses of olibanum and to 70% for analyses of dammar and mastic resin, and this is a very encouraging result. The optimizedprotocol was successfully applied on the archaeological sample G12, which was supposed to contain mastic resin and thishypothesis was confirmed by HPLC/UV and GC-MS analysis. A quantitative study of performance and the relative area of thepeaks were also performed. The extracts were analyzed by HPLC / UV and GC-MS. Concerning GC-MS analysis, samplepreparation was done through formation of TMS derivatives (trimethylsilyl) with the aim of creating a database of TMSderivatives for dammar and mastic resins. The identification of compounds characterized in this work was done according tothe literature, and corresponding tR et UV spectra. D-limonene, one of «green» solvents, has been used for the first time for theextraction of these materials, according to our knowledge and it allows a direct formation of TMS derivatives in the presence ofextraction solvent. At the same time, seven artistic samples supposed to contain a varnish based on a natural resin from theNational Gallery of Sarajevo (Bosnia and Herzegovina) were analyzed and for only one of these seven samples we found thepresence of a natural gum resin. The scientific study of Bosnian samples expands the scientific documentation in art andcultural heritage of Bosnia and Herzegovina, which encounters a difficult period after the last war (1992-1995)
Chemical study of resinous materials : olibanum, dammar and mastic : application to artistic and archaeological samples