Exploring the transition from natural to synthetic dyes in the production of 19th-century Central Asian ikat textiles

Abstract

This study focuses on the dye analysis of 26 ikat textiles present in the collection of the Arthur M. Sackler Gallery and originally collected by Dr. Guido Goldman with the aim to gain additional information about their provenance and dating. The investigation exploits the full potential of a multi-analytical approach, starting with a non-invasive survey of all the colors using fiber optic reflectance spectroscopy (FORS), which revealed the presence of indigo and insect-based red dyes. These data were used to select areas from which samples were taken and analyzed by high performance liquid chromatography diode array detector (HPLC–DAD). These results enabled most of the natural sources of dyes to be fully identified, including American cochineal (Dactylopius coccus), madder (probably Rubia tinctorum), lac (probably Kerria lacca), larkspur (Delphinum semibarbatum), pagoda tree flower buds (Sophora japonica), grape vine leaves (Vitis vinifera), indigo and tannins. Complex mixtures of dyes were present in most samples, as a result of both the ikat making process itself and traditional dyeing practices. Synthetic dyes were identified in 9 of the textiles. Samples were re-analyzed using HPLC–DAD coupled to mass spectrometry (HPLC–DAD-MS). Malachite green (basic green 4, C.I. 42000), fuchsine (basic violet 14, C.I. 42510), rhodamine B (basic violet 10, C.I. 45170) and methyl violet (basic violet 1, C.I. 42535) were identified, and a few other tentatively identified synthetic dyes (probably orange I, II and IV, rhodamine 6G, patent blue V and alizarin yellow GG) were detected. As the first synthesis of early synthetic dyes is well documented, their presence was used to refine the dating of these textiles. The contextualization of the results also appeared to support the stylistic assumption that more intricate and colorful designs with a higher level of complexity are dated earlier than simpler, larger and more graphic ones. The overall information acquired reveals a dynamic scenario and an interesting window into the dyers’ experiments and adjustments to the economic and technological changes of the nineteenth century.

Multi-Technique Investigation of Grave Robes from 17th and 18th Century Crypts Using Combined Spectroscopic, Spectrometric Techniques, and New-Generation Sequencing

“…The identification of dyes in historical objects requires sensitive and selective analytical methods because the amount of available materials is usually limited. Among them, highperformance liquid chromatography with spectrophotometric and mass-spectrometric detectors (HPLC-UV-Vis-MS) is one of the useful tools for the analysis of textile samples containing dyes [4][5][6][7][8][9]. Tandem electrospray ionization mass spectrometry (MS/MS) can identify these compounds and enables conclusions about their structures [10][11][12][13][14].…”

Bordering on Asian Paintings: Dye Analysis of Textile Borders and Mount Elements to Complement Research on Asian Pictorial Art

“…The British Museum has undertaken research on Asian dyes for several years, with the result of building an in-house database to be exploited for Asian dye identification [11][12][13]. This research, combined with information from various other sources [14][15][16][17][18][19][20][21][22][23][24][25][26][27], provides a good foundation from which to undertake further studies into Asian dyes.…”

“…In fact, dyes are generally mixtures of molecules, and some of them do not produce signals specific enough to enable their identification non-invasively, especially most yellow dyes [34,35]. Mixtures of dyes can also be difficult to identify non-invasively [23,36]. By contrast, when sampling is possible, highly detailed information relating to the molecular structure of the dye molecules can be obtained by using high-performance liquid chromatography (HPLC) [37].…”

“…The technique enables all the molecular components present in the sample to be chromatographically separated and identified singularly so that the exact plant or animal source(s) of the dye(s) are identified at the species level [38][39][40][41][42]. The identification is achieved by recording the UV/Vis absorption spectra of the dye molecules with a photo-diode array (PDA) detector [43][44][45], their fluorescence spectra with fluorescence (FL) detector [46], and/or their masses with a mass spectrometer (MS) [12,[18][19][20]22,23,47,48]. The advantages of using MS are related to the possible identification of degradation products and relevant non-coloured molecules [15,49].…”

“…Recent studies have shown the advantages of using a combined investigative approach to dye analysis, starting with non-invasive techniques and using the results obtained noninvasively to guide a selective sampling campaign that minimises the number and size of samples [23,55,56]. Although this approach represents an ideal scenario, the reality of investigations carried out on museum collections often dictates that compromises are made, mostly due to time constraints and the inability to sample certain objects due to their state of conservation or ethical considerations.…”