Marengo Emilio, Robotti Elisa, Liparota Maria Cristina, Gennaro Maria Carla
Dipartimento di Scienze e Tecnologie Avanzate, Università del Piemonte Orientale A. Avogadro Spalto Marengo 33, 15100 Alessandria, Italy.
Anal Chem. 2003 Oct 15;75(20):5567-74. doi: 10.1021/ac0300791.
The principles of quality control and multivariate statistical analysis were applied to the monitoring of the conservation state of wooden works of art. Three degradation processes (exposure to a wet atmosphere, to an acidic attack, and to UV light) were simulated on the surface of wooden boards of the XVI century and were monitored by the use of Raman spectroscopy. The resulting spectra were treated by principal component analysis, which allowed reduction of the system dimensionality. The relevant principal components were used to build multivariate control charts, namely, the Shewhart, CUSUM, and SMART (simultaneous scores monitoring and residual tracking) control charts. The Shewhart charts allowed identification of the effects due to the degradation processes. The CUSUM charts permitted identifcation of the exact moment in which the degradation treatment was started. The SMART charts provided a synthetic description of the conservation state of the wooden surface by means of only two charts: the T2 Hotelling and the DModX charts.
质量控制和多元统计分析原理被应用于对木制艺术品保存状态的监测。在16世纪木板表面模拟了三种降解过程（暴露于潮湿大气、酸性侵蚀和紫外线照射），并通过拉曼光谱法进行监测。所得光谱通过主成分分析进行处理，这使得系统维度得以降低。相关主成分被用于构建多元控制图，即休哈特控制图、累积和控制图以及SMART（同时得分监测和残差跟踪）控制图。休哈特控制图能够识别降解过程产生的影响。累积和控制图可以确定降解处理开始的确切时刻。SMART控制图仅通过两张图，即T2霍特林图和DModX图，对木质表面的保存状态提供了综合描述。
