Result and discusion In this study, we initially checked the thermal decomposition temperature for the Japanese lacquer film. Urushiols were observed as the main component in the lacquer film at 400°C. However, the thermal decomposition components indicating the lacquer film were observed at much higher levels at 500°C. As a result, we decided to use 500°C as the decomposition temperature for the GCxGC/EI and GCxGC/PI measurements. GCxGC is a powerful chromatographic separation technique that provides both boiling point and polar separations simultaneously during a single sample measurement. We detected main components 'Urushiols' in both EI and PI data. We also observed approximately 1,000 compounds in the lacquer sample using an automatic peak search function for the GCxGC/EI data. Additionally, this data showed several easily identifiable compound series such as hydrocarbons, carboxylic acids, aromatic ketones, alkyl phenols.