TY - JOUR
T1 - Unilateral NMR applied to the conservation of works of art
AU - Del Federico, Eleonora
AU - Centeno, Silvia A.
AU - Kehlet, Cindie
AU - Currier, Penelope
AU - Stockman, Denise
AU - Jerschow, Alexej
N1 - Funding Information:
Acknowledgements The authors are indebted to Niels Nielsen from the University of Aarhus, Denmark, for helpful discussions on the data analysis and would also like to thank Cyndi O’Hern and Lindsey Tyne, Pratt Institute alumni fellows, for preparing some of the samples used in this study, and Julie Arslanoglu, from The Metropolitan Museum of Art, for helpful comments. D.S. would like to acknowledge the staff of the Paper Conservation Department at The Metropolitan Museum of Art for their support in the initial stages of the project. We are also grateful to Wolfgang Schoefberger for preliminary unilateral NMR studies and to Bruker Optics for the loan of a minispec ProFiler®. This work was possible thanks to funding from the Alfred. P. Sloan Foundation, which supported the purchase of the Profile NMR-MOUSE®, as well as by funding provided by The Andrew W. Mellon Foundation, the Kress Foundation, the National Science Foundation (no. CHE-0554400), and the Camille and Hendry Dreyfus Foundation Special Grant Program in the Chemical Sciences.
PY - 2010/1
Y1 - 2010/1
N2 - In conventional NMR, samples from works of art in sizes above those considered acceptable in the field of art conservation would have to be removed to place them into the bore of large superconducting magnets. The portable permanent-magnet-based systems, by contrast, can be used in situ to study works of art, in a noninvasive manner. One of these portable NMR systems, NMR-MOUSE®, measures the information contained in one pixel in an NMR image from a region of about 1 cm2, which can be as thin as 2-3 μm. With such a high depth resolution, profiles through the structures of art objects can be measured to characterize the materials, the artists' techniques, and the deterioration processes. A novel application of the technique to study a deterioration process and to follow up a conservation treatment is presented in which micrometer-thick oil stains on paper are differentiated and characterized. In this example, the spin-spin relaxation T 2 of the stain is correlated to the iodine number and to the degree of cross-linking of the oil, parameters that are crucial in choosing an appropriate conservation treatment to remove them. It is also shown that the variation of T 2 over the course of treatments with organic solvents can be used to monitor the progress of the conservation interventions. It is expected that unilateral NMR in combination with multivariate data analysis will fill a gap within the set of high-spatial-resolution techniques currently available for the noninvasive analysis of materials in works of art, where procedures to study the inorganic components are currently far more developed than those suitable for the study of the organic components.
AB - In conventional NMR, samples from works of art in sizes above those considered acceptable in the field of art conservation would have to be removed to place them into the bore of large superconducting magnets. The portable permanent-magnet-based systems, by contrast, can be used in situ to study works of art, in a noninvasive manner. One of these portable NMR systems, NMR-MOUSE®, measures the information contained in one pixel in an NMR image from a region of about 1 cm2, which can be as thin as 2-3 μm. With such a high depth resolution, profiles through the structures of art objects can be measured to characterize the materials, the artists' techniques, and the deterioration processes. A novel application of the technique to study a deterioration process and to follow up a conservation treatment is presented in which micrometer-thick oil stains on paper are differentiated and characterized. In this example, the spin-spin relaxation T 2 of the stain is correlated to the iodine number and to the degree of cross-linking of the oil, parameters that are crucial in choosing an appropriate conservation treatment to remove them. It is also shown that the variation of T 2 over the course of treatments with organic solvents can be used to monitor the progress of the conservation interventions. It is expected that unilateral NMR in combination with multivariate data analysis will fill a gap within the set of high-spatial-resolution techniques currently available for the noninvasive analysis of materials in works of art, where procedures to study the inorganic components are currently far more developed than those suitable for the study of the organic components.
KW - Art conservation
KW - Low-field NMR
KW - Oil stains
KW - Transverse relaxation
KW - Unilateral NMR
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U2 - 10.1007/s00216-009-3128-7
DO - 10.1007/s00216-009-3128-7
M3 - Article
C2 - 19787343
AN - SCOPUS:72849151975
SN - 1618-2642
VL - 396
SP - 213
EP - 220
JO - Analytical and Bioanalytical Chemistry
JF - Analytical and Bioanalytical Chemistry
IS - 1
ER -