Bausch Florian, Khaliliyan Hajar, Tsetsgee Otgontuul, Owusu Dickson Daniel, Böhmdorfer Stefan, Rosenau Thomas, Potthast Antje
Department of Chemistry, Institute of Chemistry for Renewable Resources, BOKU University, Konrad-Lorenz-Straße 24, A-3430 Tulln, Austria.
Department of Chemistry, Institute of Chemistry for Renewable Resources, BOKU University, Konrad-Lorenz-Straße 24, A-3430 Tulln, Austria.
Spectrochim Acta A Mol Biomol Spectrosc. 2025 Jan 15;325:125103. doi: 10.1016/j.saa.2024.125103. Epub 2024 Sep 7.
Papyrus has been used for millennia to record information, for sophisticated works of art as well as mundane notes. The collection, identification, and translation of papyrus fragments therefore opens a gateway into the past. To aid the efforts to access the history recorded in papyri, we investigated the suitability of NIR spectroscopy to perform two tasks: One is to support the authentication of ancient papyri, by differentiation of papyri that were manufactured more recently and subjected to accelerated ageing to resemble the originals. The other is the extensive task to piece together papyrus fragments into readable texts again. In museums around the world, more than 100,000 ancient papyrus fragments still wait for their proper assembly, deciphering and publication. The papyrus writing-ground was analysed by near-infrared (NIR) spectroscopy, and the spectra were evaluated using principal component analysis (PCA), hierarchical cluster analysis (HCA), partial least squares discriminant analysis (PLS-DA), and self-organizing maps (SOM). Cluster analysis and PLS-DA proved to be useful tools for distinguishing modern papyri from ancient papyri which were provided by collections in Vienna and Leipzig. Neither natural nor accelerated ageing affected the classification. A PLS-DA classification model, constructed from NIR spectra of 89 model scores, detected recent Papyri samples with 100 % sensitivity and specificity, even after accelerated ageing. The identification of groups of fragments of ancient papyri based on NIR spectra and chemometry is not straightforward. HCA, which focuses on the differences between samples, only grouped the fragments of 4 out of 20 papyri correctly. SOM, which rather focuses on the similarities, grouped 6 sets of fragments correctly. An automated grouping of fragments remains difficult, since the fragments themselves are heterogeneous while similarities between unrelated ancient papyri can be large.
纸莎草纸已被使用了数千年，用于记录信息、创作精致的艺术品以及书写日常笔记。因此，纸莎草纸碎片的收集、识别和翻译为我们打开了一扇通向过去的大门。为了助力获取纸莎草纸所记录的历史，我们研究了近红外光谱法执行两项任务的适用性：一是通过区分近期制造并经过加速老化以使其类似原件的纸莎草纸，来支持对古代纸莎草纸的鉴定。另一项是将纸莎草纸碎片重新拼凑成可读文本这一艰巨任务。在世界各地的博物馆中，仍有超过10万片古代纸莎草纸碎片等待着妥善的拼接、破译和出版。通过近红外（NIR）光谱法对纸莎草纸的书写表面进行了分析，并使用主成分分析（PCA）、层次聚类分析（HCA）、偏最小二乘判别分析（PLS-DA）和自组织映射（SOM）对光谱进行了评估。聚类分析和PLS-DA被证明是区分现代纸莎草纸和由维也纳及莱比锡的藏品提供的古代纸莎草纸的有用工具。自然老化和加速老化均未影响分类。由89个模型得分的近红外光谱构建的PLS-DA分类模型，即使在加速老化后，对近期纸莎草纸样本的检测灵敏度和特异性也达到了100%。基于近红外光谱和化学计量学对古代纸莎草纸碎片组进行识别并非易事。专注于样本间差异的HCA仅正确地对20份纸莎草纸中的4份碎片进行了分组。而更侧重于相似性的SOM正确地对6组碎片进行了分组。由于碎片本身具有异质性，而不相关的古代纸莎草纸之间的相似性可能很大，因此对碎片进行自动分组仍然困难重重。
