Application of derivatization pyrolysis gas chromatography/mass spectrometry to analysis of archaeological lacquerwares

• Mixture lacquer standards were prepared and analyzed by Py-GC/MS.
• Peak groups showed platform-type shape differ from standard mountain-type shape.
• Resulting from direct Py-GC/MS were compare and confirmed by derivative Py-GC/MS.
• Revealed Ryukyu kingdom used mixture lacquer as coating material to make lacquer objects in their long history lacquer culture.

One piece from Mumujyana ruins and one piece from Urasoe Yōdore (a mausoleum), both belong to Ryukyu Kingdom, were analyzed by direct and derivative pyrolysis gas chromatograph/mass spectrometry (Py-GC/MS). Direct Py-GC/MS chromatogram at m/z = 108 of both samples showed that peaks of 3-pentadecylphenol and 3-heptadecylphenol were relatively weak, and the shape of peaks from low molecular weight component group formed a platform, different from the mountain type of the three standard Toxicodendron vernicifluum, Toxicodendron succedanea, and Gluta usitata lacquers. However, analysis of a mixture of the three kind lacquers and a sample of T. succedanea mixed with T. vernicifluum showed a similar platform shape on chromatogram at m/z = 108. In addition, in order to confirm this result, derivative Py-GC/MS was also performed, and the results are compared and discussed.