An Unusual Mural Paintings at the Charola of the Convent of Tomar: Red Lakes and Organic Binders Ana Manhita, 1 *S  ergio Martins, 1 Cristina Barrocas Dias, 1,2 Ana Cardoso, 1 Ant  onio Candeias, 1,2 Milene Gil 1 1 Laboratorio HERCULES, Universidade de  Evora, Palacio do Vimioso, Largo Marqu^es de Marialva 8,  Evora 7000-809, Portugal 2 Departamento de Quımica, Escola de Ci^encias e Tecnologia, Universidade de  Evora, Colegio Luıs Antonio Verney, Rua Rom~ao Ramalho 59,  Evora 7000-671, Portugal Received 8 October 2015; revised 1 November 2015; accepted 2 November 2015 Abstract: This work presents the results of the analysis of the organic materials (red lakes and binders) from the flesh tones, wings, and vests of the angels from the mural paintings from the Charola of the Convent of Tomar. Pyrolysis coupled to gas chromatography and mass spec- trometry (Py-GC/MS) was selected for the identification of binders, and liquid chromatography coupled to diode array and MS detection (LC/DAD/MS) was used for the identification of lakes in the red paint layers. VC 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 258–262, 2016; Published Online 17 December 2015 in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/col.22009 Key words: mural paintings; red lakes; organic binders; Py-GC/MS; LC/DAD/MS INTRODUCTION The Convent of Christ is one of the most emblematic monuments of the city of Tomar that received the classifi- cation of World Heritage by UNESCO. The oldest build- ing of the Convent is the Charola, dated from the 12th century. The Charola is a polygonal structure, with eight sides on the inside that turn into 16 sides on the outside, similarly to the Holy Sepulcher of the Mosque of Omar in Jerusalem. Over the centuries, this space has undergone several architectural renovations. The most significant was promoted by King Manuel I, presumably between 1510 and 1525. 1 The iconographic enrichment of the Charola, which was transformed into the high altar of the church, includes sculptures, oil paintings on wood and leather, stucco work, and mural paintings (Fig. 1). The mural paintings are of particular importance because they are the only example in Portugal of a monumental picto- rial cycle made exclusively with organic binders, known to date. EXPERIMENTAL Optical Microscopy A Leica DM2500 M dark field microscope was used for image acquisition of resin-mounted cross sections of samples. Red Lakes’ Extraction and Analysis Three red layer samples were selected for analysis using liquid chromatography coupled to diode array and mass spectrometry detectors (LC/DAD/MS). Samples were previously observed on a dark field microscope, and the ones showing a pink/orange fluorescence under UV illumination were chosen for LC/DAD/MS analysis. Lake extraction from the samples (<200 lg) was done accord- ing to the methodology proposed by Wouters et al. 2 The sample was extracted during 4 h with 200 lL of an hydro- fluoric acid solution, 2 lyophilized, and redissolved in *Correspondence to: Ana Manhita (e-mail: anaccm@uevora.pt) Contract grant sponsor: Fundac¸~ao para a Ci^encia e Tecnologia, through Post-Doc grant and Project PRIM’ART, funded by FCT/MEC and cofunded by Fundo Europeu de Desenvolvimento Regional (FEDER) through pro- gram COMPETE; contract grant numbers: SFRH/BPD/63552/2009, PTDC/ CPC-EAT/4769/2012. VC 2015 Wiley Periodicals, Inc. 258 COLOR research and application