Dyes of a Shadow Theatre: Investigating Tholu Bommalu Indian Puppets through a Highly Sensitive Multi-Spectroscopic Approach

Tholu Bommalu are typical leather puppets of the traditional Indian shadow theatre. Two of these objects are part of a collection in the International Puppets Museum “Antonio Pasqualino” (Palermo, Sicily, Italy), which can count on one hundred-seventy-three of artifacts. These Indian puppets were investigated to obtain information related to the use of dyes for their manufacturing through a multi-technical approach exploiting the combination of highly sensitive spectroscopic techniques. Wet cotton stubbons were used to entrap small particles of dyes on the fibers from the art objects for the consequent analyses. Visible Light Micro-Reflectance spectroscopy was employed for the preliminary identification of the molecular class of dyes directly on the swabs, while Surface Enhanced Raman Scattering allowed the identification of the specific dye. Several synthetic dyes belonging to different typologies of coloring compounds were identified. The study resulted in an interesting overview of dyes used in recent Tholu Bommalata manufacturing through the combination of micro-invasive techniques directly on the sampling substrate

New advances in dye analyses. In situ gel-supported liquid extraction from paint layers and textiles for SERS and HPLC-MS/MS Identification

To date, it is still not possible to obtain exhaustive information about organic materials in cultural heritage without sampling. Nonetheless, when studying unique objects with invaluable artistic or historical significance, preserving their integrity is a priority. In particular, organic dye identification is of significant interest for history and conservation research, but it is still hindered by analytes’ low concentration and poor fastness. In this work, a minimally invasive approach for dye identification is presented. The procedure is designed to accompany noninvasive analyses of inorganic substances for comprehensive studies of complex cultural heritage matrices, in compliance with their soundness. Liquid extraction of madder, turmeric, and indigo dyes was performed directly from paint layers and textiles. The extraction was supported by hydrogels, which themselves can undergo multitechnique analyses in the place of samples. After extraction, Ag colloid pastes were applied on the gels for SERS analyses, allowing for the identification of the three dyes. For the HPLC-MS/MS analyses, re-extraction of the dyes was followed by a clean-up step that was successfully applied on madder and turmeric. The colour change perceptivity after extraction was measured with colorimetry. The results showed ΔE values mostly below the upper limit of rigorous colour change, confirming the gentleness of the procedure

On-gel sampling for analytical investigation of dyes in pictorial artworks: new advances

While the study of inorganic components in artworks can be performed through non invasive and on site methodologies, the identification of organic materials in pictorial layers still represents a complex issue If several approaches are available for the sensitive detection of these analytes in laboratory, the sampling represents a delicate step, and it must be performed with reference to the principle on micro invasiveness This study explores the potential of an analytical procedure which takes advantage of gel substrates versatility to conduct multi analytical identification Organic compounds were directly extracted from pictorial layers in order to be analyzed by means of spectroscopic and chromatographic techniques

Acute infectious mononucleosis presenting with palpebral and periorbital edema

Introduction Almost all organs can be involved in the infection by Epstein–Barr virus and consequently, the beginning symptoms of infectious mononucleosis may be different.Materials and methods We report a case of infection by Epstein–Barr virus in a 17-year-old girl whose primary manifestation was an initially monolateral and subsequently bilateral dacryoadenitis.Results The incidence of acute dacryoadenitis by Epstein–Barr virus is valued around one case per million people per year, but it is probably underestimated: it is due to infiltration of the lacrimal gland by activated lymphocytes.Discussion An acute dacryoadenitis, especially when it affects a young adult and when bilateral, should guide the diagnostic and haematochemical and serological investigations towards a systemic disease such as infectious mononucleosis. It is almost always responsive to a systemic corticosteroid therapy, but in some cases it can progress towards a dacryocystitis and exceptionally towards the Sjögren syndrome. Appropriate and timely treatment will be able to reduce any subsequent complications.</p

Street art graffiti. Discovering their composition and alteration by FTIR and micro-Raman spectroscopy

Paints used in street art are modern materials subjected to degradation processes, which are very complex and difficult to predict without taking into account of several factors. This study investigates three outdoor murals in Lazio, – namely “graffiti”, a word now used to indicate a spontaneous street art tendency consisting in images and writings realized by spray paints in public spaces to provoke passersby -with the aim to discover materials application techniques and chemical composition and figure out whether alteration phenomena occurred. Twenty-two samples were collected, and their stratigraphy was studied by optical microscopy. Fourier Transformed Infrared spectroscopy was used to identify binders and their degradation products in paints and preparatory layers, while for characterization of organic pigments used in all different stratigraphy layers of samples micro-Raman spectroscopy analyses was carried out. Furthermore, micro-Raman spectroscopy allowed to study an unusual patina formed on the surface of a pink paint. This information is useful for artists as well as for conservators, who must face numerous issues related to the preservation of this modern and labile kind of artistic expression, very fashionable nowadays but often created without care for materials duration. Conservation issues were also deepened by interviews with several contemporary mural authors. Artists underlined how contemporary murals are a very heterogeneous means of expression. Different cultural tendencies coexisting result in different attitude towards conservation

Gel microextraction from hydrophilic paint layers. A comparison between Agar-gel and Nanorestore Gel® HWR for spectroscopic identification of madder

While non-invasive analyses are widespread for the study of inorganic components in cultural heritage, the identification of organic substances can be very challenging when sampling is forbidden. In particular, organic dyes are hardly detectable because of their low concentration and tendency to fade. Hydrogels retention and release properties make them suitable for microextraction of dyes directly from the artifact, maintaining its integrity. After extraction, the hydrogels versatility makes them ideal for a multi-analytical study of the dyes. In this work, the gel microextraction procedure was put to the test of hydrophilic paint layers. Different Agar-gel weight concentrations were tested and compared with Nanorestore Gel® High Water Retention for the extraction of madder dyes from Arabic gum paint layers. UV–vis spectroscopy and SER spectroscopy were effective in identifying the analytes. Nonetheless, the sampling mechanism and the procedure invasiveness have proved to be dependent on the hydrogels retention power

Direct gel-supported liquid extraction from paint layers: a new invisible procedure for SERS and HPLC-HRMS identification of dyes in complex matrices

The study of dyes employed in artworks is of big interest for history and conservation research, but the most critical aspect in such matter is the necessity of sampling. Dyes are easy to fade and usually low in concentration compared to inorganic components, thus, their signals in mixtures can be easily covered during non-invasive analyses. With the rise of SERS supports for minimally invasive analyses of dyes, more and more attention has been given to hydrogels. Hydrogels are substances able to hold more than 90% of water (v/v) in their three-dimensional network, showing a solid-fluid dualism [1]. This property makes them able to absorb aqueous solutions and release them in a controlled way. Besides their employment in surface cleaning [2], during the last decades it became clear hydrogels loaded with appropriate solutions could be used for direct dyes extraction from cultural heritage, for SERS identification [3]. The presented work was aimed at challenging the direct gel-supported liquid extraction (GSLE) to multi-technique dyes identification from complex paint matrices

Applying gel-supported liquid extraction to Tutankhamun’s textiles for the Identification of ancient colorants. A case study

The identification of the dyes present on a linen fragment from the tomb of Pharaoh Tutankhamun is the objective of the present study. Fiber optic reflectance spectroscopy (FORS) was applied to the archaeological sample for preliminary identification of the dyes and to better choose the extraction methodology for different areas of the sample. The innovative gel-supported microextraction with agar gel and the Nanorestore Gel® High Water Retention (HWR) gel were applied to the archaeological sample after testing of the best concentration for the extraction of the agar gels substrates, performed on laboratory mock-ups by means of UV–Vis transmittance spectroscopy. Immediately after extraction, Ag colloidal pastes were applied on the gel surface and Surface Enhanced Raman Scattering (SERS) analysis was performed directly on them. The combination of information deriving from FORS and SERS spectra resulted in the successful identification of both indigo and madder and, in hypothesis, of their degradation products