Colors and dyes of archaeological textiles from Tarapacá in the Atacama Desert (South Central Andes)

Abstract

This work concerns the study of colors and dyes identified on archaeological textiles from the Atacama Desert. The different garments and ornaments come from the excavation of two important pre-Columbian cemeteries of the Tarapacá region: Tarapacá-40 attributed to the Formative period (1100 BC–660 AD) and Pica-8 to the Late Intermediate period (900–1450 AD). For the first time, a multi-analytical approach with non-invasive techniques using FORS and SERS was applied on samples of less than 2 cm of length for physicochemical characterization of the raw materials and the dyes employed in the textile production of northern Chile. The fibers are from animal origin. Blue, green, and yellow are identified as indigo, but we cannot discard a mixture with other dyes to vary hue and shade; while carminic acid and alizarin—to a lesser extent—are found on red, orange, and brown samples. This research provides new elements for the discussion about the textile technology developed in this desertic region, its changes, and continuities along the history. Our results are compared to recent findings on neighboring regions from South-Central Andes, to improve the current knowledge and discuss the existence of dyeing textile cultural traditions.

Characterizing the Dyes of Pre-Columbian Andean Textiles: Comparison of Ambient Ionization Mass Spectrometry and HPLC-DAD

“…Each of the methods has capabilities and limitations that make using them together the best choice for cases where LC-MS/MS is not available, as is the case here at EMU and many other laboratories. Ideally, dyes would be identified completely non-invasively; fiber optic reflectance spectroscopy (FORS) and surface-enhanced Raman spectroscopy have been shown to be useful for some dyes, particularly the reds [20,21,42]. However, these techniques are not yet as widely available and used as are HPLC and MS.…”

“…The high tinting strength of most dyestuffs means that while the color of the sample may be readily visible, the actual amount of colorant present may be below the limits of detection of many analytical approaches. Degradation may complicate the identification of dye colorants, particularly those present in the fugitive yellow dyes, applications of fiber-optic reflectance spectroscopy and Raman spectroscopy [19][20][21]. With secure contexts for the materials being characterized, a great deal can be learned about the culture and technology of the textile artists, as demonstrated by Boytner [22].…”

Alizarin old and new: Extraction techniques for coloration, advances in detection methods for historical textiles and novel applications as a functional dye

“…Several studies demonstrated the benefits of using an HPLC-based system to identify alizarin from F I G U R E 5 A, SERS spectra of fibre samples from Pica 8 archaeological textiles from the Atacama Desert (South America), reused from Ref. 22 ; B, HPLC profile of a dye extracted from an ancient Egyptian textile object, reused from Ref. 124 ; C, HPLC profiles of the dyes extracted from two Finnish textile fragments, reused from Ref.…”

Identification of Historical Textiles via Non-destructive Spectroscopic Analysis and Multivariate Cluster Analysis

“…Therefore, developing a non-destructive approach to studying Norwich textiles is expected to be extended to understanding fabrics of similar substrate and age; and to extending the approach to other textiles and dyed substrates (e.g., paper). Typical use of FORS in the literature identi es dyes in textiles via manual interpretation, 18, [23][24][25][26][27][28][29] with only a handful of works employing multivariate analyses. [30][31][32][33] The present work builds on the limited body of multivariate analysis of FORS spectra by rst, signi cantly increasing dataset size; second, expanding analysis to identifying spectral regions that correspond to multivariate clustering; and lastly, validating these ndings with selected HPLC-MS analyses.…”

“…Further analysis is underway to discern whether this observation should be attributed to the HPLC validation set being small, or to speci c chromophore bands in FORS, as many reports have suggested. 18,22,23,25,[33][34][35][36][37] Experimental…”