PYROLYSIS-GAS CHROMATOGRAPHY MASS-SPECTROMETRY OF NATURAL RESINS USEDFOR ARTISTIC OBJECTS

Eight resins used as protective layers for paintings, small sculptures , jewelries and artistic furniture, namely, Manila copal, colophony, V enice turpentine, elemi, shellac, dammar, sandarac and mastic were sub jected to pyrolysis gas chromatography-mass spectrometry (PY-GC-MS). S ignificant mass spectral ions were monitored in each pyrogram. A table for identification of such resins based on the most significant ions in the mass spectra of the pyrolysis fragments is proposed. The result s of PY-GC-MS analysis of a sample from the earth globe Giovanni Enriq ues, attributed to the Venetian geographer Vincenzo Coronelli (1650-17 18) (Museo della Specola, Department of Astronomy, University of Bolog na), are reported as an example of practical application of the method to a real artistic sample.