Voras Zachary E, deGhetaldi Kristin, Wiggins Marcie B, Buckley Barbara, Baade Brian, Mass Jennifer L, Beebe Thomas P
Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA; UD Surface Analysis Facility, University of Delaware, Newark, DE 19716, USA.
Department of Art Conservation, University of Delaware, Newark, DE 19716, USA; Winterthur-University of Delaware Program in Art Conservation, Winterthur, DE, USA.
Appl Phys A Mater Sci Process. 2015 Nov;121(3):1015-1030. doi: 10.1007/s00339-015-9508-2. Epub 2015 Oct 3.
Time-of-flight secondary ion mass spectrometry (ToF-SIMS) has recently been shown to be a valuable tool for cultural heritage studies, especially when used in conjunction with established analytical techniques in the field. The ability of ToF-SIMS to simultaneously image inorganic and organic species within a paint cross section at micrometer-level spatial resolution makes it a uniquely qualified analytical technique to aid in further understanding the processes of pigment and binder alteration, as well as pigment-binder interactions. In this study, ToF-SIMS was used to detect and image both molecular and elemental species related to CdS pigment and binding medium alteration on the painting (1905-1906, The Barnes Foundation) by Henri Matisse. Three categories of inorganic and organic components were found throughout and co-localized in cross-sectional samples using high spatial resolution ToF-SIMS analysis: (1) species relating to the preparation and photo-induced oxidation of CdS yellow pigments (2) varying amounts of long-chain fatty acids present in both the paint and primary ground layer and (3) specific amino acid fragments, possibly relating to the painting's complex restoration history. ToF-SIMS's ability to discern both organic and inorganic species via cross-sectional imaging was used to compare samples collected from to artificially aged reference paints in an effort to gather mechanistic information relating to alteration processes that have been previously explored using μXANES, SR-μXRF, SEM-EDX, and SR-FTIR. The relatively high sensitivity offered by ToF-SIMS imaging coupled to the high spatial resolution allowed for the positive identification of degradation products (such as cadmium oxalate) in specific paint regions that have before been unobserved. The imaging of organic materials has provided an insight into the extent of destruction of the original binding medium, as well as identifying unexpected organic materials in specific paint layers.
飞行时间二次离子质谱（ToF-SIMS）最近已被证明是文化遗产研究中的一种宝贵工具，特别是当它与该领域已有的分析技术结合使用时。ToF-SIMS能够在微米级空间分辨率下同时对油漆横截面内的无机和有机物质进行成像，这使其成为一种独特的、有资格帮助进一步理解颜料和粘合剂变化过程以及颜料-粘合剂相互作用的分析技术。在本研究中，ToF-SIMS被用于检测和成像与亨利·马蒂斯的画作（1905 - 1906年，巴恩斯基金会）上硫化镉颜料和粘合剂变化相关的分子和元素种类。通过高空间分辨率的ToF-SIMS分析，在横截面样品中发现了三类无机和有机成分并确定了它们的共定位情况：（1）与硫化镉黄色颜料的制备和光致氧化有关的物质；（2）油漆和底层中存在的不同数量的长链脂肪酸；（3）特定的氨基酸片段，可能与这幅画复杂的修复历史有关。ToF-SIMS通过横截面成像辨别有机和无机物质的能力被用于将从画作上采集的样品与人工老化的参考油漆进行比较，以便收集与之前使用μXANES、SR-μXRF、SEM-EDX和SR-FTIR所探索的变化过程相关的机理信息。ToF-SIMS成像提供的相对较高灵敏度与高空间分辨率相结合，使得能够在特定油漆区域中明确识别出之前未观察到的降解产物（如草酸镉）。对有机材料的成像深入了解了原始粘合剂介质的破坏程度，并在特定油漆层中识别出了意想不到的有机材料。
