TitreCombining XANES, ICP-AES, and SEM/EDS for the study of phytate chelating treatments used on iron gall ink damaged manuscripts
Type de publicationArticle de revue
Année de publication2011
AuteursVéronique Rouchon, Eleonora Pellizzi, Maroussia Duranton, Frederik Vanmeert, Koen Janssens
JournalJournal of Analytical Atomic Spectrometry
Numéro12
Pagination2434-2441
Résumé

Many historical documents written with iron gall inks are endangered by the corrosive effects of these inks. In this work, a combination of complementary analytical methods was used for the first time in order to study the ''phytate'' process which is used in conservation studios to stabilize damaged manuscripts. This process consists of an antioxidant treatment performed by means of a calcium phytate (CP) solution, followed by a deacidification treatment performed with a calcium carbonate (CC) solution. The antioxidant treatment capitalizes on the properties of myo-inositol hexaphosphoric acid (phytic acid) that inhibits iron through chelation. In order to use relatively low acidic solutions, the pH of the CP solution is increased up to values between 5 and 6, which is in the range of the CP precipitation threshold. This study was performed on laboratory samples made of paper impregnated with iron gall ink and artificially aged in climatic chambers. It aims to investigate how the CP precipitate impacts the efficiency of the treatment. Side effects, such as elemental losses and deposits, were measured by means of several analytical techniques (Fe–K Edge XANES, SEM/EDS, and ICP-AES). These measurements were crosschecked with a ready to use colour spot test made of bathophenanthroline impregnated paper. It appeared that the CP treatment should necessarily be followed by the deacidification treatment in order to achieve long term stability. The precipitation of CP in the treating solution does finally not impact the efficiency of the treatment despite the fact that it should theoretically lower the availability of phytate to chelate iron. A scenario is proposed to explain this point.

URLhttps://hal.archives-ouvertes.fr/hal-01447280/document
DOI10.1039/c1ja10185d
Champ de recherche: 
combining xanes icpaes and semeds for the study of phytate chelating treatments used on iron gall ink damaged manuscripts journal of analytical atomic spectrometry pmany historical documents written with iron gall inks are endangered by the corrosive effects of these inks in this work a combination of complementary analytical methods was used for the first time in order to study the phytate process which is used in conservation studios to stabilize damaged manuscripts this process consists of an antioxidant treatment performed by means of a calcium phytate cp solution followed by a deacidification treatment performed with a calcium carbonate cc solution the antioxidant treatment capitalizes on the properties of myoinositol hexaphosphoric acid phytic acid that inhibits iron through chelation in order to use relatively low acidic solutions the ph of the cp solution is increased up to values between 5 and 6 which is in the range of the cp precipitation threshold this study was performed on laboratory samples made of paper impregnated with iron gall ink and artificially aged in climatic chambers it aims to investigate how the cp precipitate impacts the efficiency of the treatment side effects such as elemental losses and deposits were measured by means of several analytical techniques fek edge xanes semeds and icpaes these measurements were crosschecked with a ready to use colour spot test made of bathophenanthroline impregnated paper it appeared that the cp treatment should necessarily be followed by the deacidification treatment in order to achieve long term stability the precipitation of cp in the treating solution does finally not impact the efficiency of the treatment despite the fact that it should theoretically lower the availability of phytate to chelate iron a scenario is proposed to explain this pointp httpshalarchivesouvertesfrhal01447280document 101039c1ja10185d veronique rouchon eleonora pellizzi maroussia duranton frederik vanmeert koen janssens
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