Monday, August 08, 2011

More on DSS in Analytical and Bioanalytical Chemistry

MORE ON THE DEAD SEA SCROLLS in Analytical and Bioanalytical Chemistry, collected by Joseph Lauer. Both articles are behind a subscription wall.
Provenance studies on Dead Sea scrolls parchment by means of quantitative micro-XRF

Timo Wolff, Ira Rabin, Ioanna Mantouvalou, Birgit Kanngießer, Wolfgang Malzer, Emanuel Kindzorra and Oliver Hahn


In this study, we address the question of the provenance and origin of the Dead Sea Scrolls manuscripts. A characteristic low ratio of chlorine to bromine, corresponding to that of the Dead Sea water, may serve as an indicator for local production. For this aim we developed a non-destructive procedure to determine the Cl/Br ratio in the parchment of these manuscripts. Micro-X-ray fluorescence (μ-XRF) measurements of a large number of parchment and leather fragments from the Dead Sea Scrolls were analyzed with a routine we developed based on fundamental parameter quantification. This routine takes into account the absorption of the collagen matrix and the influence of the different sample thicknesses. To calculate the representative Cl/Br ratio for each fragment, we investigated the lateral homogeneity and determined the total mass deposition using the intensity of the inelastically scattered, characteristic tube radiation. The distribution of the Cl/Br ratios thus obtained from the μ-XRF measurements make it possible to distinguish fragments whose origin lies within the Dead Sea region from those produced in other locations.

Solid-state and unilateral NMR study of deterioration of a Dead Sea Scroll fragment

A. Masic, M. R. Chierotti, R. Gobetto, G. Martra, I. Rabin and S. Coluccia


Unilateral and solid-state nuclear magnetic resonance (NMR) analyses were performed on a parchment fragment of the Dead Sea Scroll (DSS). The analyzed sample belongs to the collection of non-inscribed and nontreated fragments of known archaeological provenance from the John Rylands University Library in Manchester. Therefore, it can be considered as original DSS material free from any contamination related to the post-discovery period. Considering the paramount significance of the DSS, noninvasive approaches and portable in situ nondestructive methods are of fundamental importance for the determination of composition, structure, and chemical–physical properties of the materials under study. NMR studies reveal low amounts of water content associated with very short proton relaxation times, T 1, indicating a high level of deterioration of collagen molecules within scroll fragments. In addition, 13C cross-polarization magic-angle-spinning (CPMAS) NMR spectroscopy shows characteristic peaks of lipids whose presence we attribute to the production technology that did not involve liming. Extraction with chloroform led to the reduction of both lipid and protein signals in the 13C CPMAS spectrum indicating probable involvement of lipids in parchment degradation processes. NMR absorption and relaxation measurements provide nondestructive, discriminative, and sensitive tools for studying the deterioration effects on the organization and properties of water and collagen within ancient manuscripts.