Paintings SIMS analysis

In an article published in Analytical Chemistry in 2004, Keune and Boon [2004a] present the application of ToF-SIMS analysis to a paint cross-section. The sample used was from the panel painting The Descent from the Cross (Museo del Prado, Madrid) by the early Flemish painter Rogier van der Weyden (1399/1400 1464). Scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX) and infrared microscopy were also used to complete and confirm the results. 

K. Keune and J. J. Boon, Enhancement of the static SIMS secondary ion yields of lipid moieties by ultrathin gold coating of aged oil paint surfaces, Surface and Interface Analysis, 36, 1620 1628 (2004b). 

Thanks to the extensive literature on Aujj and the related smaller gold cluster compounds, plus some new results and reanalysis of older results to be presented here, it is now possible to paint a fairly consistent physical picture of the AU55 cluster system. To this end, the results of several microscopic techniques, such as Extended X-ray Absorption Fine Structure (EXAFS) [39,40,41], Mossbauer Effect Spectroscopy (MES) [24, 25, 42,43,44,45,46], Secondary Ion Mass Spectrometry (SIMS) [35, 36], Photoemission Spectroscopy (XPS and UPS) [47,48,49], nuclear magnetic resonance (NMR) [29, 50, 51], and electron spin resonance (ESR) [17, 52, 53, 54] will be combined with the results of several macroscopic techniques, such as Specific Heat (Cv) [25, 54, 55, 56,49], Differential Scanning Calorimetry (DSC) [57], Thermo-gravimetric Analysis (TGA) [58], UV-visible absorption spectroscopy [40, 57,17, 59, 60], AC and DC Electrical Conductivity [29,61,62, 63,30] and Magnetic Susceptibility [64, 53]. This is the first metal cluster system that has been subjected to such a comprehensive examination. 

FIGURE 36.1 GC/MS chromatogram, acquired in single ion monitoring (SIM) mode, of the proteinaceous fraction of a paint sample from the Etruscan tomb Tomba deUa Quadriga Infernale (Sarteano, Siena, Italy) [19], containing egg protein.The analysis entailed hydrolysis, purification using a CIS pipette tip and sUylation of the amino acids with N-methyl-N-(t-butyldimethylsilyl) trifluoroacetamide (MTBSTFA) in pyridine. 

Van den Berg et al. [185] has compiled a database of SIMS spectra of the most common inorganic pigments. ToF-SIMS offers some interesting possibilities for the spatially resolved analysis of (mixtures of) pigments in paint cross sections. However, the specific selectivity of the technique for different pigments needs to be taken into account. A further point of concern is interference with the embedding medium of the paint cross sections (matrix effect). 

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