Analysis of Natural and Synthetic Organic Lakes and Pigments by Chromatographic and Mass Spectrometric Techniques

Abstract

AbstractThis chapter aims to provide an overview of natural and synthetic organic lakes and pigments and of how their analysis by chromatography and mass spectrometry can provide useful information in the examination of works of art. The characteristics of natural organic colourants are reviewed, including information on their provenance and uses in the production of lakes; information on the date of production, availability as paint products and application in artworks of the most important synthetic organic pigments is also provided. This chapter specifically illustrates the state-of-the-art of organic pigments analysis by high performance liquid chromatography with different detectors, and by gas chromatography – mass spectrometry also coupled to analytical pyrolysis. Different mass spectrometry based techniques used both as detector and directly applied on a sample or its extract are also presented. Particular attention is paid to sample preparation; further issues related to difficulties in finding relevant standards or reference materials and understanding photo-degradation processes occurring in degraded organic pigments are also discussed. Several case studies are presented, showing the potentialities of liquid chromatography interfaced with mass spectrometry in determining properties of the samples which can be of assistance for assessing the provenance, dating or even the authenticity of a painting.KeywordsHigh performance liquid chromatographyMass spectrometryOrganic lakesSynthetic organic pigmentsPaint materials