Identification of Dyes on Old Textiles

Schweppe, Helmut

doi:10.2307/3179569

Cited by 21 publications

(17 citation statements)

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“…Hot pyridine and DMF are described in the literature for the extraction of indigo dyes from textile samples [27,28]. Nevertheless, indigotin (1, Table 1) was not observed in the DMF extract, and only a small chromatographic peak with t r =12.5 min was detected (data not shown), likely indirubin, a compound which is normally present at variable concentration in the indigo dyes.…”

Section: Evaluation Of the Extraction Proceduresmentioning

confidence: 99%

“…Two milligrammes of woad dyed wool was placed in capped vials with 0.5 mL of DMF and heated at 100°C for 15 min [27]. Vials were then cooled and solvent evaporated under vacuum.…”

Section: Dmf Methodsmentioning

confidence: 99%

“…Long ago, Schweppe [27] identified the natural dyes on the fibres without taking them up into solution, based on the fact that natural mordant dyes form lakes of various colours with different mordant ions. Concerning the fibres dyed with mixtures of natural dyes and blue indigoid dyes, Schweppe [27] pointed out that the indigo should be removed from the fibre by repeated boiling with dimethylformamide (DMF) until the solvent remains colourless.…”

Section: Introductionmentioning

confidence: 99%

“…Concerning the fibres dyed with mixtures of natural dyes and blue indigoid dyes, Schweppe [27] pointed out that the indigo should be removed from the fibre by repeated boiling with dimethylformamide (DMF) until the solvent remains colourless. Once the indigo has been removed, the yellow or the red dyes are left behind and could be identified by forming the various coloured lakes.…”

Section: Introductionmentioning

confidence: 99%

“…When indigoids dyestuffs are present in the fibre, the use of DMF [27], hot pyridine [28], MeOH/DMF [11] or dimethylsulfoxide (DMSO) [21] for the residue solubilisation is recommended instead of MeOH or MeOH/H 2 O, since indigotin and indirubin are insoluble in these solvents [11,21].…”

Section: Introductionmentioning

confidence: 99%

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Extracting natural dyes from wool—an evaluation of extraction methods

et al. 2011

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The efficiency of eight different procedures used for the extraction of natural dyes was evaluated using contemporary wool samples dyed with cochineal, madder, woad, weld, brazilwood and logwood. Comparison was made based on the LC-DAD peak areas of the natural dye's main components which had been extracted from the wool samples. Among the tested methods, an extraction procedure with Na 2 EDTA in water/DMF (1:1, v/v) proved to be the most suitable for the extraction of the studied dyes, which presented a wide range of chemical structures. The identification of the natural dyes used in the making of an eighteenth century Arraiolos carpet was possible using the Na 2 EDTA/DMF extraction of the wool embroidery samples and an LC-DAD-MS methodology. The effectiveness of the Na 2 EDTA/DMF extraction method was particularly observed in the extraction of weld dye components. Nine flavone derivatives previously identified in weld extracts could be identified in a single historical sample, confirming the use of this natural dye in the making of Arraiolos carpets. Indigo and brazilwood were also identified in the samples, and despite the fact that these natural dyes were referred in the historical recipes of Arraiolos dyeing, it is the first time that the use of brazilwood is confirmed. Mordant analysis by ICP-MS identified the widespread use of alum in the dyeing process, but in some samples with darker hues, high amounts of iron were found instead.

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Section: Evaluation Of the Extraction Proceduresmentioning

confidence: 99%

“…Two milligrammes of woad dyed wool was placed in capped vials with 0.5 mL of DMF and heated at 100°C for 15 min [27]. Vials were then cooled and solvent evaporated under vacuum.…”

Section: Dmf Methodsmentioning

confidence: 99%