Relevance of Cross-Section Analysis in Correct Diagnosis of the State of Conservation of Building Materials As Evidenced by Spectroscopic Imaging

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• 作者：Nagore Prieto-Taboada ; Olivia G贸mez-Laserna ; Irantzu Martinez-Arkarazo ; Mar铆a 脕ngeles Olazabal ; Juan Manuel Madariaga
• 刊名：Analytical Chemistry
• 出版年：2013
• 出版时间：October 15, 2013
• 年：2013
• 卷：85
• 期：20
• 页码：9501-9507
• 全文大小：400K
• 年卷期：v.85,no.20(October 15, 2013)
• ISSN：1520-6882

文摘

In the present work the need to use cross-section analysis as a routine procedure to characterize physiochemical damage on building materials was evaluated using a combination of spectroscopic imaging techniques based on Raman spectroscopy, X-ray fluorescence spectroscopy (XRF), and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM鈥揈DX). First, samples for cross-section analysis required special preparation to avoid the loss of soluble and weakly anchored compounds and thereby ensure the representativeness of the analysis. To this end, samples were dry drilled and fractured with a single blow rather than cut to avoid friction. Cross-section analysis allowed surface deposition (crusts and patinas) to be differentiated from penetrating pollution and the affected depth to be determined. Elemental and molecular distributions were obtained to establish the origin of the compounds/elements found. Moreover, establishing the depth reached by the pollutant, which depends on the material porosity, can help to determine the physicochemical form of the pollutant. Finally, SEM鈥揈DX images allowed surface and internal cracks, as well as the causes of these physical stresses, to be identified. As a result, surface analysis alone was shown to lead to incomplete or even incorrect conclusions that can be avoided by using cross-section analysis as a routine procedure when assessing the state of conservation of building materials.