Please cite this article in press as: I. Petroviciu, et al., Investigation of natural dyes in 15th c. documents seal threads from the Romanian Academy Library, by LC-DAD-MS (triple quadrupole), Journal of Cultural Heritage (2017), http://dx.doi.org/10.1016/j.culher.2017.05.015 ARTICLE IN PRESS G Model CULHER-3240; No. of Pages 8 Journal of Cultural Heritage xxx (2017) xxx–xxx Available online at ScienceDirect www.sciencedirect.com Case study Investigation of natural dyes in 15th c. documents seal threads from the Romanian Academy Library, by LC-DAD-MS (triple quadrupole) Irina Petroviciu a,∗ , Florin Albu b , Ileana Cretu c , Marian Virgolici d , Andrei Medvedovici e a National Museum of Romanian History (MNIR), 030026 Bucharest, Romania b S.C. Agilrom Scientific SRL, 077190 Voluntari, Ilfov, Romania c National Museum of Art of Romania (MNAR), 010063 Bucharest, Romania d “Horia Hulubei” National Research Institute for Physics and Nuclear Engineering, IRASM, 077125 Magurele, Ilfov, Romania e Department of Analytical Chemistry, Faculty of Chemistry, University of Bucharest, 050663 Bucharest, Romania a r t i c l e i n f o Article history: Received 30 January 2017 Accepted 29 May 2017 Available online xxx Keywords: Natural dyes Liquid chromatography Mass spectrometry Documents seal threads Red a b s t r a c t Dyes and biological sources in 40 samples from red seal threads in 38 documents issued by the Chancery of Moldavia between 1460 and 1503 were investigated by liquid chromatography with UV-Vis (DAD) and mass spectrometric (MS) detection. Lac dye (Kerria lacca Kerr), redwood type (Caesalpinia spp.) and madder (Rubia sp.), as individual dyes or in combinations, were responsible for the colour in all the dyed yarns while tannins were present in more than half of the total number of samples. The presence of major dyes, such as alizarin, purpurin, laccaic acid A and soluble redwood — a marker compound for Caesalpinia species were observed by both DAD and MS detectors while minor compounds (rubiadin, anthragallol, xanthopurpurin, munjistin, flavokermesic acid etc.) were only detected by mass spectrometry. Single stage MS detection was used in the Full Scan mode followed by data processing through Ion Extraction according to the molecular ions of compounds in the database. Tandem MS detection (MS 2 ) was also achieved, through using the Product Ion Scan operating mode. Identification of dyes was made according to retention time, UV-Vis and MS data, based on information collected on standards — dyes and dyed fibers. The biological sources detected are discussed as compared with those identified in ecclesiastical embroideries from the same period, ordered by the same Prince, Stephan the Great (1457–1504). © 2017 Elsevier Masson SAS. All rights reserved. 1. Introduction Natural dyes were the only source of color from Antiquity and until the synthetic dyes were introduced to the market, in 1856. Initially used only locally, later subject of commercialization, iden- tification of natural dyes in historical textiles may add consistent information about the period and place an object was made. Such information is based on literature records about the natural dyes first trade, new commercial routes or regulation of use [1–3]. The interest for natural dyes in textiles from Romanian collec- tions turned up in the identification of dyes and biological sources in the most representative local ones, dating from the 15th to the 20th century [4–9]. A special interest was given to a collection of textiles from the long reign of Stephan the Great (1457–1504), the ruler of Moldavia for almost 50 years in the second half of the 15th century [10]. Investigation of red dyes in twelve ecclesiastical ∗ Corresponding author. E-mail addresses: petroviciu@yahoo.com, irinapetroviciu@mnir.ro (I. Petroviciu). textiles with donor inscriptions, from this period, preserved at Putna Monastery, showed that the combination of lac dye and madder was used for most of the objects, while kermes, the most expensive red dye at that time [11] was preferred for the more important objects, as those especially designed for Stephan’s wife, Princess Maria of Mangop [6,12,13]. A collection of documents with hanging seals emitted by the Chancery of Moldavia in the time of Stephan the Great is preserved at the Romanian Academy Library (BAR). The documents were studied from several perspectives but never as regards the colour source in the hanging seals red silk threads [14]. High performance liquid chromatography with UV-Vis detec- tion (DAD) is the standard set up for investigation of natural dyes, since its development by Wouters, in 1985 [15–21]. In the last 15 years, mass spectrometers were increasingly exploited, in various configurations [22–28]. Their use increases the level of cer- titude in identifications by introducing new criteria — the molecular ion (for single stage MS detectors) and the product ion scan mode (for tandem MS instruments). MS detection provides lower detec- tion limits for most of the dyes used in historical textiles. Such increased sensitivity is obtained by the reduction of the noise level, http://dx.doi.org/10.1016/j.culher.2017.05.015 1296-2074/© 2017 Elsevier Masson SAS. All rights reserved.