Search

• New insight on the journey of "Byzantine gems" from the East to the West of the Empire. • The gems of the relic of St. John the Baptist and its reliquary are analyzed for the first time. • The presence of a rare and exquisite example of Balas ruby was identified in the relic. • The investigation improves knowledge on ancient gems traveling across Europe. Gems, especially from remote areas, were highly demanded and valued in Byzantine times, often used for sacred Imperial purposes. Because of their imperishable nature, they were often re-used over time and many of them passed, one way or another, from East to Western Europe. The history of the gems set in Byzantine relics that survived in medieval Europe is often impossible to reconstruct. The exceptional opening of the relics of St. John the Baptist in Siena, 200 years after the last inspection, has made it possible to study the magnificent gems that adorn it. Spinels, rubies, sapphires and other gems from oriental geographies, along with high quality glasses used together regardless of their monetary value, were identified in the relic and its reliquary case through gemological analysis and portable Raman spectroscopy, once again demonstrating the vital contribution of the trans-disciplinary approach in the study of ancient art goldworkings. [ABSTRACT FROM AUTHOR]

Saliva is an easily sampled matrix containing a variety of biochemical information, which can be correlated with the individual health status. The fast, straightforward analysis of saliva by vibrational (ATR-FTIR and Raman) spectroscopy is a good premise for large-scale preclinical studies to aid translation into clinics. In this work, the effects of saliva collection (spitting/swab) and processing (two different deproteinization procedures) were explored by principal component analysis (PCA) of ATR-FTIR and Raman data and by investigating the effects on the main saliva metabolites by reversed-phase chromatography (RPC-HPLC-DAD). Our results show that, depending on the bioanalytical information needed, special care must be taken when saliva is collected with swabs because the polymeric material significantly interacts with some saliva components. Moreover, the analysis of saliva before and after deproteinization by FTIR and Raman spectroscopy allows to obtain complementary biological information. [ABSTRACT FROM AUTHOR]

[Display omitted] • Raman/SERS are proposed for the screening of poorly soluble pharmaceuticals. • Multivariate analysis to correlate concentration to Raman/SERS signals. • The analytical approach was applied to wastewater analysis. • DFT studies allowed to identify characteristic spectral patterns. Pharmacologically active compounds can be dispersed in nature during their manufacture, consumption, and disposal. In this study three pharmaceutical ingredients (acetaminophen, indomethacin and acetazolamide), commonly found in wastewaters, were studied in aqueous environment by Raman spectroscopy. Their spectroscopic properties were computed using density functional theory methods, and a combined atomistic/continuum description of the aqueous solution. The theoretical study allowed to explore the potential energy surface, to identify stable structures, and to accurately predict their Raman response in solution. Given the relevance of the determination of these compounds, their spectral information were related to their concentration level in water and synthetic wastewater by Raman multivariate regression models (partial least squares and Gaussian process regression), reaching limit of detection down to millimolar (investigated range 2.5 – 40 mM, 1.25 – 5 mM, and 0.25 – 5 mM for acetaminophen, indomethacin and acetazolamide, respectively). However, since in real samples pharmaceutical ingredients are usually found at trace level, the suitability of a more performing techniques such as surface-enhanced Raman spectroscopy was evaluated, which enabled us to lower the detection limit of one order on magnitude at least. The quality of the obtained surface-enhanced Raman spectra for the selected molecules should also be highlighted respect to those currently available in the literature. Surface-enhanced Raman analysis of acetazolamide, especially, shows promising features for the development of a sensitive (down to nanomolar) and highly specific analytical method. [ABSTRACT FROM AUTHOR]

Data on the abundance and distribution of Anthropogenic Marine Debris (AMD) on the coastal areas of the northern Tyrrhenian coast are still scarce. The objective of this study is to characterize, in terms of size, color, morphology and polymeric nature, the Large Microplastics (LMPs), i.e., plastic objects within 1 and 5 mm, sampled on three beaches located within the coastal macro-area of the Pelagos Sanctuary, an international protected zone in the north-western Mediterranean. The beaches have similar morphological characteristics but different degrees of urbanization. LMPs were sampled seasonally for one year. The polymeric nature of a representative subsample of the collected LMPs was investigated using a portable Raman instrument, to assess the feasibility of in situ characterization. In this study, 26,486 items were sorted by typology (Expanded Polystyrene-EPS, fragments, and resin pellets), size, and for fragments and resin pellets, also by color and chemical nature. Statistical data on the quantity, density, type, spatial distribution, and seasonality of the sampled LMPs are presented. Differences in LMP abundance and composition were detected among sites. A seasonality trend emerges from our statistical analysis, depending on both LMP typology and urbanization degrees of the beaches. Our data do not show the existence of a relationship between the size of the investigated MPs and their color, while they suggest that the type of polymer influences the degree of fragmentation. This underlines the need to further investigate the mechanisms leading to the production and dispersion of MPs in coastal areas, taking into account both the urbanization of the beach, and therefore the possible sources of input, and the different types of MPs. Finally, a Raman portable instrument proved to be a valuable aid in performing in situ polymeric characterization of LMPs. [ABSTRACT FROM AUTHOR]

The unicellular microalga Euglena gracilis has always been considered the ideal alga to investigate photoreceptive responses and systems, and it has been the subject of hundreds of articles. Moreover, because of its detectable photoreceptor, it has been given a key role in the evolution of photoreception, from single and simple cells to complex visual system of higher organisms. In this article, we report the Raman spectra recorded in vivo on photoreceptors of E. gracilis and Bos taurus retina. The almost perfect superimposability (correlation coefficient r = 0.955) of these spectra states that the Euglena possesses a photoreceptor with the same structural characteristic of a vertebrate photoreceptor, i.e. a stack of membrane layers embedding rhodopsin‐like proteins. Raman spectra recorded in vivo on photoreceptors of E. gracilis after hydroxylamine treatment further confirm our findings, which should lead to a reconsideration of most of the scientific literature on algae photoreception and eye evolution. [ABSTRACT FROM AUTHOR]

Man has always used writing to be able to communicate, express, and disseminate his thoughts. In time, many different coloured extracts of plant and animal origin have been used to produce inks; after the development of synthetic chemistry, artificial and synthetic dyes started to be widely exploited. The end of the 19th century marked great technological and industrial innovations in commercial production of artists' materials. To reveal ink formulations and build a database of red inks by different producers, we developed a multi-analytical approach and investigated a collection of writing inks produced in France in the late 19th – early 20th century. The materials used as binders, additives, dyes, and pigments have been investigated by high performance liquid chromatography coupled with diode array and tandem mass spectrometric detectors (HPLC-DAD-MS2), in situ derivatisation pyrolysis coupled with gas chromatography-mass spectrometry (Py(HMDS)-GC/MS), surface enhanced Raman (SERS, TLC-SERS) and X-Ray Fluorescence spectroscopies. Several dyes and pigments were detected, showing that the French ink's formulations of the early days of synthetic dye industry were based on rhodamine B and 6G , eosin Y , rose Bengal and methyl or crystal violet. Instead, as binder and additives only gum Arabic and shellac resin have been identified, respectively. Mass spectrometry also allowed us to detect possible by-products of the synthesis of ink's dyes and even early degradation products, that can be used for ink identification in historical writings and drawings. Our studies can pave the way to investigate inks in historical samples by introducing ultra-sensitive chromatographic and mass spectrometric methods in the array of analytical tools available to the chemist. [Display omitted] • We applied a multianalytical method to the analysis of historical red inks. • We applied Raman spectroscopy and TLC-SERS to study mixtures of organic pigments. • We investigated secondary components by HPLC-DAD-MS2. • We characterized binders and additives by Py(HMDS)-GC/MS. • We revealed a trend in French ink formulations from late 19th – early 20th cent. [ABSTRACT FROM AUTHOR]

• A multi-technique approach has been used to study Max Ernst's masterpiece. • Vis-NIR imaging revealed a preparatory drawing and pentimenti. • Conscious use of colour palette which includes both traditional and synthetic pigments. • ER-FTIR analysis evidenced Zn oxalates and Zn metal soaps as degradation products. The Attirement of the Bride , painted by Max Ernst in 1940, is permanently on display in the Peggy Guggenheim Collection (PGC) in Venice. Within the framework of a larger study of materials and techniques of works by Ernst at the PGC, researchers carried out a series of non-invasive analyses. A combined approach based on Vis-NIR multispectral imaging, Raman Spectroscopy, X-Ray Fluorescence (XRF), and External Reflection Fourier Transform Infrared Spectroscopy (ER-FTIR), was conducted insitu in the museum galleries. In addition, two micro-samples were analysed with SEM-EDS and μ-Raman. This approach produced vital information on the preparatory drawing, the pentimenti , the pigments, the extenders and the alteration products present in the painting. The results showed also the presence of a white preparatory layer, under the pictorial one and above the canvas, composed by lithopone (a mixture of zinc sulphide and barium sulphate), basic lead carbonate and calcium carbonate. The latter compound is probably present also as an extender. The palette included both traditional and new synthetic, commercial pigments, used as primary colours or in mixtures. Moreover, in several areas of the painting, zinc oxalates have been identified as alteration products and more rarely, zinc metal soaps, which could also be present as additives in the paint tube. These analyses revealed the masterful and innovative painting technique of this pioneer of Surrealism. [ABSTRACT FROM AUTHOR]

In this paper, we report a multidisciplinary approach for the analytic study and the reconstruction of the ancient colour used for Roman sarcophagi. For this purpose, we adopted the three-dimensional (3D) digital technology and found it to be a valuable tool for the identification, documentation and reconstruction of the ancient colour. This technology proved to be an excellent link between archaeological knowledge and scientific analyses. Therefore, 3D digital technologies would effectively facilitate the exchange of information and collaboration between experts in various disciplines. This is extremely important in order to obtain demonstrable results in a new area of study, such as polychrome Roman sarcophagi (and the ancient polychromy and gilding on the marble). In this study, the digital 3D model of Ulpia Domnina's sarcophagus (National Roman Museum in Rome, inv. no. 125891) has been used to identify both the pigments and the techniques of application used, and to explore the potential of emerging technologies in the reconstruction and visualization of the ancient colour. [ABSTRACT FROM AUTHOR]