Rev Anal Chem 30 (2011): 153–164 © 2011 by Walter de Gruyter • Berlin • Boston. DOI 10.1515/REVAC.2011.101 Identifi cation of natural yellow, blue, green and black dyes in 15th – 17th centuries Ottoman silk and wool textiles by HPLC with diode array detection Turkan Yurdun 1 , Recep Karadag 2, *, Emre Dolen 3 and products and others are used by the food industry ( Gonz á lez Mohammad S. Mubarak 4, * et al. 2005 ). They have been analysed, initially by thin layer chromatography (TLC); however, high performance liquid 1 Faculty of Pharmacy , Department of Pharmaceutical chromatography (HPLC) coupled with either diode array Toxicology, Marmara University, 34668 detection (DAD) ( Wouters 1985 , Wouters and Verhecken Haydarpasa-Istanbul , Turkey 1989a , b , Wouters 1990 , Novotn á et al. 1999 , Orska-Gawrys´ 2 Laboratory for Natural Dyes , Faculty of Fine Arts, et al. 2003 , Surowiec et al. 2006 , Karapanagiotis et al. 2007 , Marmara University, 34718 Acibadem-Kadik ö y-Istanbul , Deveoglu et al. 2009 , 2010 , Karadag et al. 2010 ) or mass Turkey , e-mail: [email protected] spectrometric detection (MS) ( Szostek et al. 2003 , Balakina 3 Faculty of Pharmacy , Department of Analytical et al. 2006 , Karapanagiotis and Chryssoulakis 2006 , Rafa ë lly Chemistry, Marmara University, 34668 et al. 2008 ) has recently been successfully utilised to iden- Haydarpasa-Istanbul , Turkey tify the active colouring ingredients in historic yarns, textiles 4 Department of Chemistry , The University of Jordan, fi bres ( Wouters 1992 ), historic maps ( Blanc et al. 2006 ), Amman 11942 , Jordan, e-mail: [email protected] printed documents and paintings ( Daniilia et al. 2008 ), and *Corresponding authors icons ( Karapanagiotis et al. 2005 , 2007 ). Historical textiles were dyed with natural dyes which were mainly of plant or insect origin. Dye identifi cation of histori- Abstract cal textiles is usually based on comparison with known refer- ences. In our case, dye sources used as references were as High performance liquid chromatography coupled with diode follows. array detection (HPLC-DAD) was utilised for the identifi ca- tion of dyestuffs in different plants such as dyers weld, gall- Weld ( Reseda luteola L.) nut, walloon oak, woad, indigo shrub and cochineal. The most important dyestuffs detected were natural yellow, green, beige, This dye plant is one of the most important natural yellow black and blue dyes which are found in historical textiles. In dyes used to produce fast yellows. Weld appears to have been addition, reversed-phase HPLC with DAD was employed in used in Europe since prehistoric times. It is likely to have been the identifi cation of natural dyes in extracts of historical silk widely used in the Mediterranean area in the Hellenistic period art objects, from historical textiles and newly dyed silk fi bres. and in the Roman Empire ( Cardon 2007 ) era. Weld was used in The objects examined were from the 15th to 17th century the 1st century Masada textiles, 3rd century Palmyra textiles, Ottoman period and belong to the collection of the Topkapi 13th century Seljuk carpets and 15th – 20th century Ottoman Palace Museum in Istanbul. Fibres with yellow, blue, black, textiles for yellow and green colours ( Karadag 2007 ). beige and green colours were selected for the analysis. Dye components were identifi ed in the extracts of 11 art objects Woad ( Isatis tinctoria L.) analysed; both insect and plant dyes were detected. This plant appears to have been utilised since very early times Keywords: art objects; dyestuff; ellagic acid; HPLC-diode for dyeing textiles and, possibly even earlier, for body paints. array detection; indigotin; luteolin. Egypt was one of the early centres of woad dyeing; woad was most probably one of the plant sources of blue dye men- tioned in documents from the Pharaonic and Ptolemaic peri- Introduction ods. Moreover, woad dyeing processes were well known to the Egyptians of the Hellenistic period ( Cardon 2007 ). Woad Identifi cation of colouring materials in an art object related was also used in the 1st century Masada textiles, 3rd century to cultural heritage has been the focus of signifi cant attention Palmyra textiles, 13th century Seljuk carpets and 15th – 20th because of their importance in the development of appropri- century Ottoman textiles for blue and green colours ( Karadag ate conservation and restoration strategies. Natural dyes have 2007 ). There is a dispute, however, about whether dyeing with the advantages that their production implies the use of renew- indigo was fi rst developed in India or in Egypt. The name able resources, cause minimum environmental pollution and indigo , the most important dye of the ancient world, sug- have a low risk factor to human health. Some natural dyes gests India. For hundreds of years, perhaps even thousands are utilised by the pharmaceutical industry as a basis for drug of years, India was the greatest producer of indigo and the 154 T. Yurdun et al.: Identifi cation of dyestuffs with HPLC-DAD most important indigo plant is Indigo ( Indigofera tinctoria L.) Fibres of animal origin (such as silk and wool) have basic ( Cardon 2007 ). chemical groups, mainly amino and carboxyl groups. In the mordanting process, acidic-hydrolysed metal ions form Gall oak ( Quercus infectoria Olivier) bonds with the basic amino and carboxyl groups on the fi bres. Similarly, basic groups on the dye molecules form bonds with The medicinal and tannin properties of galls, as well as the the acidic metal ions on the mordanted fi bres. At the end of reaction of gall extract with iron to produce blue-black colour- the dyeing process (fi bre – metal ion – dye molecule), strong ations, have been known since antiquity ( Cardon 2007 ). The chemical bonds are formed. galls of Q uercus infectoria were known in Mesopotamia, Fibres are immersed in the aqueous metal salt solution Hellenistic and Roman times, for their production for dyeing. (mordant bath) and heated to 90° C for 1 h and then the mor- The galls used were of black colour and were used with mixed danted fi bres are removed from the bath and left to dry in the dye plants and with mixed dye insects in 13th century Seljuk open air. The dyeing procedures were performed in accordance carpets and 15th – 20th century Ottoman textiles. In addition, with the historical dyeing methods ( Karadag 2007 ). In the dye the plant was used for mordanting ( Karadag 2007 ). bath, the ratio of fi bres to dye extract is 1:25. For example, 25 g of dye extract is used for 1 g of wool. To prepare the dye Walloon oak ( Quercus ithaburensis Decaisne) bath, dyestuffs of insects or plants are extracted with water at 90 ° C for 1 h and then the residues are fi ltered. Mordant fi bres The acorn caps of Quercus ithaburensis were used for black are immersed in the dye bath and the temperature is gradu- dyeing in the Ottoman textiles ( Karadag 2007 ). ally raised to 90 ° C and is kept at this value for approximately In this paper, we have employed HPLC-DAD for the iden- 30 – 60 min. The dye bath is left to cool down to around 30° C tifi cation of dyestuffs in different plants such as dyers weld, and then the dyed fi bres are removed from dye bath, squeezed, gallnut, walloon oak, woad, indigo shrub and cochineal. rinsed thoroughly with water and dried in the open air in the shade. Mordanting and dyeing procedures employed in this study are similar to procedures adopted by other researchers Materials and methods ( Mikropoulou et al. 2009 , Zakogianni et al. 2010). In this investigation, silk and wool were dyed with fi ve dif- Chemicals ferent plant dyes and one insect dye (weld = Reseda luteola L., gall oak = Quercus infectoria Olivier, acorn caps= Quercus All reagents employed in this investigation were of analyti- ithaburensis Decaisne, dyer ’ s sumac = Cotinus coggygria cal grade and were used as received, unless stated otherwise. Scop., cochineal = Dactylopius coccus Costa) and two indigo- High purity water was obtained by passing water through a tins, one from Isatis tinctoria L. and the other from Indigofera Milli-Q treatment system (Millipore, Bedford, MA, USA) tinctoria L., as this was used in historical procedures. and the HPLC mobile phase was prepared using Milli-Q water. The following standard materials were obtained from Extraction procedure commercial sources and used as references: ellagic acid and gallic acid from Sigma (Steinheim, Germany), luteolin and The samples were prepared as follows: newly dyed silk and apigenin, fi setin from Roth (Karlsruhe, Germany), natural wool samples ( Schweppe 1993 , Karadag 2007 ) were obtained indigotin (production from Isatis tinctoria L. or Indigofera using weld= Reseda luteola L., gall oak = Quercus infectoria tinctoria L.) from Kremer Pigmente GmbH & Co. KG Olivier, acorn caps = Quercus ithaburensis Decaisne, dyer ’ s (Munich, Germany). Silk and wool reference samples dyed sumac = Cotinus coggygria Scop., cochineal = Dactylopius with dyes weld, gallnut, walloon oak, woad, cochineal, indigo coccus Costa and indigotin (from Isatis tinctoria L. and from shrub (indigo production from Indigofera tinctoria L.) were Indigofera tinctoria L.) according to historical procedures used as dyed standards. The standard coloured pieces of silk and were prepared in the Laboratory of Natural Dyes, Faculty and wool were prepared in the Laboratory of Natural Dyes, of Fine Arts, Marmara University. Dyestuffs were extracted Faculty of Fine Arts, Marmara University. directly from dye plants (weld, gallnut, walloon oak, cochi- neal and indigotin). Alternatively, mordant silk (undyed Mordanting and dyeing procedures fi bres) and wool were extracted and dyestuffs were extracted from historical textile samples. The mordanting and dyeing of wool fi bres were performed Dyestuff extraction was performed according to previously according to literature procedures as described below described methods ( Wouters 1985 , Wouters and Verhecken ( Karadag and Dolen 1992 , Schweppe 1993 , Karadag 2007 ).