A mass spectrometric study on tannin degradation within dyed woolen yarns

Natural tannins from various plants have been used throughout human history in textile dyeing, often as mordant dyes. The ageing behavior of these dyes is a challenge in conservation science, requiring a thorough knowledge of the textile–mordant-dye system. In this work, we analyzed reference wool yarns dyed with natural tannins from oak gallnuts, walnut (Juglans regia), and catechu (Acacia catechu), after artificial ageing. To gain insights on the composition of the dyestuffs and on how they aged, an analytical procedure based on extraction with Na2EDTA/DMF (ethylenediaminetetraacetic acid/dimethylformamide) and high-performance liquid chromatography (HPLC) analysis using high-resolution mass spectrometry detection was used. Since conventional reversed-phase (RP) columns usually show poor retention efficiency of highly polar compounds such as tannins, an RP-amide embedded polar group stationary phase was used to achieve optimal retention of the most polar compounds. Tannins from oak gallnuts showed little degradation after ageing, while a significant increase in the content of hydroxybenzoic acids was observed for tannins from walnut and catechu. Finally, the analytical procedure was applied to characterize the tannin dyes in historical tapestries from the 15th to 16th century, and the results were discussed in comparison with the reference yarns

The analysis of the Saltzman Collection of Peruvian dyes by high performance liquid chromatography and ambient ionisation mass spectrometry

Yarn samples from the Saltzman Collection of Peruvian dyes were characterized by several different analytical techniques: high performance liquid chromatography with both diode array detection (HPLC-DAD) and electrospray ionisation with tandem mass spectrometry (HPLC-ESI-Q-ToF), direct analysis in real time (DART) mass spectrometry and paper spray mass spectrometry. This report serves primarily as a database of chemical information about the colorants in these dye materials for those studying ancient South American textiles and their colorants. We also provide a comparison of the results obtained by currently widespread HPLC techniques with those of two different ambient ionisation direct mass spectrometry methods to highlight the advantages and disadvantages of these approaches

Revealing the organic dye and mordant composition of Paracas textiles by a combined analytical approach

The object of this study is a wide selection of dyed cotton and camelid samples from an important collection of 2000-year-old Paracas textiles, now at the Museo Nacional de Arqueología, Antropología e Historia del Perú (MNAAHP; Lima; Peru) and at the National Museum of World Culture (NMWC; Gothenburg; Sweden). The threads, chosen as representative of the whole palette, were selected from eighteen different textiles. A combined spectroscopic and spectrometric analytical approach was selected to characterize the organic and inorganic composition of this wide set of samples. In particular, technical photography was used to gain a general overview of the samples, X-ray fluorescence (XRF) was employed for identifying the mordants and mapping the elemental distribution in the threads, while liquid chromatography coupled with diode array detector and with high-resolution mass spectrometry (HPLC–DAD, HPLC–HRMS) were used for characterizing organic dye composition. This study provides fundamental information on the mordants or other inorganic auxiliaries used in the dyeing processes, rarely investigated up to now, and to the varieties of vegetal sources employed in Paracas textiles. The widening of the Andean dyestuff database is highly important not only to acquire knowledge on Paracas culture, but also to ease the dye characterization of archaeological textiles from the Peruvian region and South American area in general.[Figure not available: see fulltext.]

Heritage Science Contribution to the Understanding of Meaningful Khipu Colours

This work is the first scientific study of khipu dyes and inorganic mordants and auxiliaries, paving the way for a new approach to understanding khipus’ meaningful materiality, technology, and colours. Khipus have usually been described as “Andean knotted records”, but they are much more than complex knotted cords: a great part of the information encoded resides in khipus’ incredible colours. The objects of this study are two Wari khipus, 1932.08.0001 and 1932.08.0002, now at the Museum of World Culture in Gothenburg, Sweden. After a morphological study of the khipus, the objects were imaged with multiband imaging (MBI) as an aid for the sampling decisional process. The khipus were then analysed non-invasively by X-ray fluorescence (XRF) spectroscopy on selected areas of particular interest. The khipus were consequently sampled for elemental characterisation by micro-XRF, and liquid chromatography coupled with high-resolution mass spectrometry (HPLC–HRMS) for characterising the organic dye composition. This paper presents a part of the results of the project “Meaningful materials in the khipu code”, with the intent to shed light on the difficulties and possibilities of investigating khipu colours and dyestuffs. MBI and XRF revealed unforeseeable structural characteristics, such as remnants from a heavily degraded thread in an area of missing thread wrapping and a dual-coloured thread that was previously deemed single-coloured. The organic dyes identified by HPLC–HRMS comprised indigoids, cochineal, and an unknown flavonoid-based dyestuff. XRF of the inorganic components revealed associations of several elements with specific colours

Multianalytical approach to characterize composition and degradation processes of synthetic high-fashion textiles from the Nanni Strada Design Studio archives

Synthetic textiles are constituents of heritage objects and garments often displayed in museum collections or preserved in archives, presenting unprecedented and specific conservation challenges. These issues need to be addressed assessing degradation processes, and developing targeted restoration and preventive conservation practices. The present work aims at characterizing the composition of high fashion garments and design textiles by Nanni Strada conserved in the archives of Nanni Strada Design Studio (Milan). To identify the chemical composition of the fibers used for the manufacturing, and to investigate the degradation processes affecting the objects, the materials were investigated by Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), Evolved Gas Analysis coupled to Mass Spectrometry (EGA-MS), and multi-shot Pyrolysis coupled to Gas Chromatography and Mass Spectrometry (Py-GC/MS). The results will contribute to a better knowledge of the chemical properties of the textiles produced in the 1970s, and to plan conservation and exhibition strategies

HPLC-DAD and HPLC-ESI-MS-MS profiles of hydroalcoholic extracts of Chamaemelum nobile and Mentha pulegium, and study of their antihemolytic activity against AAPH-induced hemolysis

Chamaemelum nobile and Mentha pulegium are two herbs used in traditional medicine throughout the world, including Algeria. The present research aimed to study the phenolic composition of C. nobile (CN) and M. pulegium (MP) hydroalcoholic extracts, as well as their antioxidant and antihemolytic effects in AAPH-induced hemolysis on human erythrocytes. Colorimetric estimation of total polyphenols, total flavonoids, flavones and flavonols and condensed tannins showed that CN was richer in total flavonoids, flavones and flavonols and condensed tannins than MP, while MP was richer in total polyphenols. A total of 46 compounds were found using HPLC/DAD and HPLC/ESI-MS-MS analysis, of which 39 were identified. All these identified compounds are divided into five structural groups; phenolic acids, quinic acid esters, flavonoids, caffeic acid oligomers and fatty acids. For the CN, 27 compounds were identified. In contrast, for the MP, only 18 compounds were identified. Both extracts showed good antioxidant activity in vitro. The IC50 for DPPH radical scavenging activity were 19.98 +/- 0.91 mu g/mL for MP and 52.77 +/- 1.53 mu g/mL for CN. The MP had a reducing power of 223.74 +/- 1.08 mg ascorbic acid equivalent/g extract, while CN's was 130.65 +/- 1.69 mg Asc E/g. Both extracts were also significantly effective and in a dose-dependent manner in reducing AAPH-induced oxidative damage on erythrocyte membranes with IC50s of 127.48 +/- 3.14 mu g/mL for CN and 129.52 +/- 2.15 mu g/mL for MP. Lipid peroxidation induced by AAPH and estimated by MDA levels revealed that both extracts significantly reduced MDA levels at doses of 200 and 300 mu g/mL, particularly MP. Our findings provide evidence that C. nobile and M. pulegium have a considerable protective effect on the erythrocyte membrane against free radicals generated by AAPH. (C) 2022 SAAB. Published by Elsevier B.V. All rights reserved