A study of degradation of historic parchment using small-angle X-ray scattering, synchrotron-IR and multivariate data analysis

Abstract

Parchment has been in use for thousands of years and has been used as the writing or drawing support for many important historic works. A variety of analytical techniques is currently used for routine assessment of the degree of denaturation of historic parchment; however, because parchment has a heterogeneous nature, analytical methods with high spatial resolution are desirable. In this work, the use of small-angle X-ray scattering (SAXS) and synchrotron-IR (SR-IR) was examined in conjunction with multivariate data analysis to study degradation of an extended set of historic parchment samples, and particularly to investigate the effect of lipids and the presence of iron gall ink on the degradation processes. In the data analysis, shrinkage temperature, lipid content, sample age, presence of ink and accelerated degradation were included. The analysis of loading factors in partial least-squares regression and principal component analyses based on SAXS, SR-IR and other analytical and descriptive data reveals the effect of lipid removal on diffraction patterns, and lipids are found to cause the degradation process in parchment to accelerate. The effect of iron gall ink is also evident, although the mechanism of ageing is different to that of natural ageing in the absence of ink. In addition, a historic parchment score from ca. 1750 is examined, demonstrating the significant effect of iron gall ink, and lipids and inorganic soiling on its increased degradation.

A study of the deterioration of aged parchment marked with laboratory iron gall inks using FTIR-ATR spectroscopy and micro hot table

“…Two variations of Laboratory Iron Gall ink formulations were studied: one with only the two mentioned ingredients and no other additive, denoted as LIG ink, and another with added gum arabic, LIGG ink. 10 ATR-FTIR spectra of inked parchment areas in LIGG specimens at various ageing times. a full spectra; b amide I and II regions; c peak fitting of the amide I and II region in unaged specimen; d peak fitting of the amide I and II region in aged specimen (2 days); e peak fitting of the amide I and II region in aged specimen (32 days).…”

“…Parchment artefacts, such as the Dead Sea Scrolls, The Vinland Map and J. S. Bach manuscripts have been the research focus for conservators and conservation scientists, investigating deterioration pathways and effective methods for conservation [3][4][5][6][7]. These studies provided insight regarding the parchment deterioration routes and mechanisms [8][9][10].…”

Variation in the sorption properties of historic parchment evaluated by dynamic water vapour sorption

“…are kept in museums, archives or libraries; and in order to ensure the continued preservation of this valuable historical material, it is important to understand the changes which take place in the structure of the material over time [1][2][3][4]. Parchment is a complex natural material made from processed, untanned animal (goat, sheep or calf) skin.…”

The effects of hydration on the collagen and gelatine phases within parchment artefacts

“…As well as the distribution described of collagen and gelatine through parchment, there are also specific loci of gelatine that seems to relate to the presence of hair holes in samples [5], this may be due to elevated levels of endogenous lipid in these areas that seems to correlate with collagen degradation [6]. Other agents such as metal based inks also lead to localised collagen degradation around inked areas throughout the depth of the parchment sheets [7].…”