Analytische Chemie
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Material studies of inks
(2017)
The course presents panorama of historic writing inks, their use the methods of their identification. First, we discuss the possible types of the inks and show how one can determine these types using very simple instrumentation.
The change of the inks from those based on soot to the iron-gall inks commonly used in the Middle Age constitutes the second half of the course.
Two main types of inks coexisted in Early Medieval times: carbon inks and iron-gall inks. Many variations within these types existed, depending on the source of raw materials and their proportion. In addition to these, an intermediate mixed type of ink, with both iron and carbon as colouring agents, was sometimes used, especially in early Arab manuscripts.
Two projects are being conducted currently at the Bundesanstalt für Materialforschung und -prüfung (BAM) concerning the analysis of inks with Raman spectroscopy. The first one aims at comparing the spectra of different carbon inks from Antiquity to the Middle Ages with Raman spectroscopy, while the second one focuses on the identification and comparison of mixed inks.
For the first project, several carbon inks were made using different sources of carbon (pine soot, olive oil soot, date seeds charcoal etc.) and various binders (fish glue, gum Arabic, proteinic binder etc.), following antique recipes. These inks were then analysed with Raman spectroscopy and fitted with the “two-peaks” and the “three-peaks” models following the procedure described by Goler et al., to help spotting differences between the spectra, depending on the recipe. Some samples were then disposed in an ageing chamber at 80°C and 60% RH and analysed again in order to determine whether changed in the spectra are observable. The procedure proposed by Goler et al. to date inks with Raman spectroscopy was also evaluated during this process. Although several carbon inks could be distinguished from their spectra, no differences were seen between aged and fresh samples. Furthermore, experimental conditions were found to have such a significant influence that reliable dating of inks through Raman spectroscopy seems dubious.
Over the last few years, the Federal Institute for material research (BAM, Berlin) together with the Centre for the Study of Manuscript Cultures (CSMC, University of Hamburg) have initiated a systematic material investigation of black inks produced from Late Antiquity to the Middle Ages (ca. fourth century CE–fourteenth/fifteenth centuries CE), aimed primarily at extending and complementing findings from previous sporadic studies. Part of this systematic investigation has focused on Egyptian Coptic manuscripts, and the present preliminary study is one of its outputs. It centres on a corpus of 45 Coptic manuscripts—43 papyri and 2 ostraca—preserved at the Palau-Ribes and Roca-Puig collections in Barcelona. The manuscripts come from the Monastery of Apa Apollo at Bawit, one of the largest monastic settlements in Egypt between the Late Antiquity and the Early Islamic Period (sixth–eighth centuries CE). The composition of their black inks was investigated in situ using near-infrared reflectography (NIRR) and X-ray fluorescence (XRF). The analyses determined that the manuscripts were written using different types of ink: pure carbon ink; carbon ink containing iron; mixed inks containing carbon, polyphenols and metallic elements; and iron-gall ink. The variety of inks used for the documentary texts seems to reflect the articulate administrative system of the monastery of Bawit. This study reveals that, in contrast to the documents, written mostly with carbon-based inks, literary biblical texts were written with iron-gall ink. The frequent reuse of papyrus paper for certain categories of documents may suggest that carbon-based inks were used for ephemeral manuscripts, since they were easy to erase by abrasion.