Is this tar? Analytical pyrolysis to study the chemical composition of Alberto Burri's paint materials

Alberto Burri, among the artists of the 20th century, was known for using some of the most complex and iconic “paint” techniques of this period, which entailed using a mixture of traditional and modern materials. The chemical composition of the materials used in his works of art is difficult to unravel given that he employed a wide variety of both natural and synthetic organic substances. Analytical pyrolysis coupled with gas chromatography and mass spectrometry (Py-GC-MS) was used to investigate the chemical composition of two works produced in 1950, belonging to the Gobbi and Catrami series of paintings, respectively. The analysis was used to investigate the chemical composition of the paint materials used in these two similar works of art and to highlight any differences in the chemical composition of the paint materials. Analytical pyrolysis was used to identify the chemical composition of the black tar-like materials used in both paintings. Pine pitch was identified in both paintings through the use of Py-GC-MS, while only one painting was characterized by a bituminous material. The molecular composition of the pine pitch gave valuable insights into the type of approach used to produce this material. Various combinations of alkyd paint, drying oil, polysaccharides, triterpenoid resin, and cellulose nitrate were found in the two paintings.