In-situ pyrolysis and silylation for analysis of lipid materials used in paint layers

Summary Although pyrolysis coupled with gas chromatography and mass spectrometry (Py-GC-MS) is a useful technique for the rapid characterization of the organic materials used by artists, diagnostic pyrolysis products bearing polar groups, for example carboxylic acids, require derivatization (e. g. methylation) before GC separation. In this study we propose the use of hexamethyldisilazane (HMDS) as an effective on-line derivatizing reagent to prepare the trimethylsilyl (TMS) derivatives of fatty acids released from the pyrolysis of fats. Pyrolysis in combination with HMDS has been applied to the analysis of lipid materials employed as painting media, for example siccative oils and egg.