Comparison of oil and egg tempera paint systems using time-of-flight secondary ion mass spectrometry

Method development for binding media analysis in painting cross‐sections by desorption electrospray ionization mass spectrometry

“…Ionization methods such as laser desorption or secondary ion mass spectrometry (SIMS) have shown to be quite successful in the analysis of samples from painted surfaces . Time‐of‐flight SIMS (TOF‐SIMS) specifically has proven to be quite effective in providing high mass and spatial resolution in determining the type and location of binding media within a painting cross‐section . However, TOF‐SIMS requires extensive sample preparation and challenging operational conditions, e.g.…”

“…7,8 Time-of-flight SIMS (TOF-SIMS) specifically has proven to be quite effective in providing high mass and spatial resolution in determining the type and location of binding media within a painting crosssection. [9][10][11] However, TOF-SIMS requires extensive sample preparation and challenging operational conditions, e.g. ultra-high vacuum, that may be cost and resource prohibitive to many conservation scientists.…”

ToF–SIMS imaging of molecular-level alteration mechanisms in Le Bonheur de vivre by Henri Matisse

“…Using this ability it was possible to observe mass fragments related to hydrolytic breakdown of the long-chain fatty acids comprising the binding medium component and also their interaction with CdS pigment. As shown in previous studies, long-chain fatty acids (such as palmitic and stearic) have been imaged in negative-mode in paintings ranging from the fourteenth to the twentieth centuries and are used here to estimate binding medium degradation due to pigment oxidation forcing acidification of the binding medium leading to hydrolytic breakdown of the long-chain fatty acid components of the binding medium [38, 44]. In addition, the formation of oxalates was observed in several of the paint samples, a product that is likely due to pigment–binder interactions resulting from photo-oxidation and/or reactions exacerbated by the application of unoriginal organic materials during previous restoration campaigns.…”

“…Long-chain fatty acids have been previously identified using ToF–SIMS analysis in easel paintings containing drying oil and egg tempera (egg yolk) that date to the fifteenth-century thus it is surprising to encounter such a low signal for palmitic and stearic acids in a painting dating to 1905/6 [38, 44]. Analysis using gas chromatography–mass spectrometry confirmed the presence of palmitic, stearic, and azelaic acids, the latter confirming the presence of a partially un-oxidized drying oil (see Fig.…”

“…Additionally, GC–MS studies of aged binding media have identified certain amino acids that are expected to be stable during the expected humidity and temperature fluctuations resulting from storage and display of works of art [46, 47]. Building on this foundation, recent studies have demonstrated the ability of Tof–SIMS to distinguish between egg and animal glue proteins found in paint cross sections [37, 38]. From these studies, it is possible to use the amino acid hydroxyproline to distinguish collagen proteins from egg yolk proteins by univariate methods as the amino acid hydroxyproline is only found in collagen protein and is identified by the unique mass fragment C 4 H 8 NO + .…”