Spectroscopic analysis used to uncover the original paint colour of the Helsinki Government Palace tower clock faces

The paint stratigraphy of the two clock faces from the tower clock of the Government Palace in Helsinki (Finland) was analysed in order to determine their original colour before restoration works. Paint cross-section samples from both clock faces were analysed by confocal Raman microscopy and scanning electron microscopy coupled to an energy dispersive X-ray spectrometer (SEM-EDS). The results revealed the complex superimposition of paint layers applied over the original black colour. FTIR/ATR analyses proved that the original paint was prepared with linseed oil-resin media. Most likely not all of the different layer colours were visible. Some of the layers were likely to have been a primer or for rust protection.Peer reviewe

Are children playgrounds safe play areas? Inorganic analysis and lead isotope ratios for contamination assessment in recreational (Brazilian) parks

In city playgrounds, there is a potential risk of harming children’s health by contamination coming from anthropogenic activities. With the aim to determinate the sources and the risk of hazardous elements, soil samples were collected in 19 selected playgrounds of different urban and rural areas from the Rio Grande do Sul state (Brazil). The concentration of 23 metals and metalloids and lead isotopic ratios were determined by ICP-MS. The methodology proposed here, firstly, classified the parks according to the average metal content by means of the NWACs (Normalized-and-Weighted Average Concentrations) and assess the contamination risk determining the Contamination Factors (CFs). Finally, statistical tools (correlation analysis and principal component analysis) were used to identify the most important contamination sources. The statistical tools used, together with lead isotopic composition analysis of the samples, revealed that coal combustion is the main source of contamination in the area. Vegetation was identified as a barrier for the contamination coming from the city. Nonetheless, some of the soils present a possible toxicological risk for humans. In fact, Cr, Sb, and Pb concentrations were higher than the Residential Intervention Values (VIRs) defined by the Environmental Protection Agency of the State of São Paulo, also in Brazil

Nanominerals and potentially hazardous elements from coal cleaning rejects of abandoned mines: Environmental impact and risk assessment

Soils around coal mining are important reservoir of hazardous elements (HEs), nanominerals, and ultrafine compounds. This research reports and discusses the soil concentrations of HEs (As, Cd, Cr, Cu, Ni, Pb, and Zn) in coal residues of abandoned mines. To assess differences regarding environmental impact and risk assessment between coal abandoned mines from the Santa Catarina state, eighteen coal cleaning rejects with different mineralogical and chemical composition, from eight abandoned mines were collected. Nanominerals and ultra-fine minerals from mining-contaminated areas were analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscope (HR-TEM), providing new information on the mineralogy and nano-mineralogy of these coal residues. The total contents of 57 elements (HEs, alkali metals, and rare earth elements) were analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The calculation of NWACs (Normalized Average Weighted Concentration), together with the chemometric analysis by Principal component analysis (PCA) confirmed the variability of the samples regarding their city and their mine of origin. Moreover, the results confirmed the existence of hotspots in mines near urban areas

Evidence of mercury sequestration by carbon nanotubes and nanominerals present in agricultural soils from a coal fired power plant exhaust

Mercury (Hg) in agricultural soils could have negative effects on the environment and the human health. The exposure to high level of Hg through different absorption pathways, such as ingestion and diet through soil-plant system could permanently damage developing foetus of animals and humans. With the aim to assess the potential environmental and health risk and to study the behaviour and fate of Hg from agricultural soils to the environment, 47 soil samples were collected around a thermoelectric power plant in the Santa Catarina (Brazil). The Hg concentration measured by inductively coupled plasma mass spectrometry (ICP-MS) ranged from 0.16 to 0.56 mg kg−1. The distribution obtained by kriging interpolation allowed the identification of the main pollution sources. To see the morphology and composition of soil samples, field emission scanning electron microscopy (FE-SEM) and high resolution transmission electron microscopy (HR-TEM) were used combined with energy dispersive X-ray spectroscopy (EDS), showing that the carbon nanotubes and magnetite as nanomineral contributed to Hg retention. The mentioned molecular characterization, and the low Contamination Factors (CF) values obtained, suggested that there is low risk to the food security of the agro-ecosystems area near to the CFPP in the terms of Hg inputs and contamination

Comparison between non-invasive methods used on paintings by Goya and his contemporaries: hyperspectral imaging vs. point-by-point spectroscopic analysis

International audienc

Nanominerales y elementos potencialmente peligrosos de la limpieza con carbón rechazan las minas abandonadas: impacto ambiental y evaluación de riesgos

Soils around coal mining are important reservoir of hazardous elements (HEs), nanominerals, and ultrafine compounds. This research reports and discusses the soil concentrations of HEs (As, Cd, Cr, Cu, Ni, Pb, and Zn) in coal residues of abandoned mines. To assess differences regarding environmental impact and risk assessment between coal abandoned mines from the Santa Catarina state, eighteen coal cleaning rejects with different mineralogical and chemical composition, from eight abandoned mines were collected. Nanominerals and ultra-fine minerals from mining-contaminated areas were analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscope (HR-TEM), providing new information on the mineralogy and nano-mineralogy of these coal residues. The total contents of 57 elements (HEs, alkali metals, and rare earth elements) were analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The calculation of NWACs (Normalized Average Weighted Concentration), together with the chemometric analysis by Principal component analysis (PCA) confirmed the variability of the samples regarding their city and their mine of origin. Moreover, the results confirmed the existence of hotspots in mines near urban areas.Los suelos alrededor de la minería del carbón son una importante reserva de elementos peligrosos (ES), nanominerales y compuestos ultrafinos. Esta investigación informa y analiza las concentraciones en el suelo de EE (As, Cd, Cr, Cu, Ni, Pb y Zn) en residuos de carbón de minas abandonadas. Para evaluar las diferencias con respecto al impacto ambiental y la evaluación de riesgos entre las minas abandonadas de carbón del estado de Santa Catarina, se recolectaron dieciocho rechazos de limpieza de carbón con diferentes composiciones mineralógicas y químicas, de ocho minas abandonadas. Los nanominerales y los minerales ultrafinos de las áreas contaminadas por la minería se analizaron mediante difracción de rayos X (DRX), microscopía electrónica de barrido de emisión de campo (FE-SEM) y microscopio electrónico de transmisión de alta resolución (HR-TEM), que proporcionaron nueva información sobre La mineralogía y nano-mineralogía de estos residuos de carbón. El contenido total de 57 elementos (HEs, metales alcalinos y elementos de tierras raras) se analizó mediante espectrometría de masas de plasma de acoplamiento inductivo (ICP-MS). El cálculo de los NWACs (Concentración ponderada promedio normalizada), junto con el análisis quimiométrico por análisis de componentes principales (PCA) confirmó la variabilidad de las muestras con respecto a su ciudad y su mina de origen. Además, los resultados confirmaron la existencia de hotspots en minas cerca de áreas urbanas

A rapid routine methodology based on chemometrics to evaluate the toxicity of commercial infant milks due to hazardous elements

The toxicity and the health risk assessment associated to the presence of some hazardous elements (HEs) in dried (infant formula and powdered) milks due to manufacturing and packaging process, raw materials used, environmental conditions, etc. need to be determined. With this aim, a new methodology based on the combination of health risk quotients and nonsupervised (as cluster analysis (CA) and principal component analysis (PCA)) chemometric techniques is proposed in this study. The methodology was exemplifed using the concentration of 27 elements, some of them HEs, measured in 12 powdered milk samples produced for children and adults in Brazil and Colombia. The concentration values were obtained by inductively coupled plasma-mass spectrometry (ICP-MS) after acid microwave digestion. Elemental concentrations vary depending upon the type of milk (initiation, growing-up, follow-on milks and adult milks). However, hazard quotients (HQ) and carcinogenic risk (CR) values showed no risk associated to the presence of HEs on milks. The methodology designed made possible to conclude that adults’ milks are more characteristic of elements naturally present in milk. Children milks present major presence of trace and minor elements. Between infant milks, sample H, designed for babies between 12 and 36 months, was identifed as of poor quality. Moreover, it was possible to deduce that while the fortifcation process applied to children powdered milks is a probable metal and metalloid source, together with the manufacturing, the skimming process is not a contamination source for milks.Springer New Yor

In-situ multi-analytical characterization of original and decay materials from unique wall mirrors in the House of Gilded Cupids, Pompeii

Abstract The House of Gilded Cupids (Regio VI, Insula 16, 7, 38) was unquestionably one of the most important residences of Ancient Pompeii, where important archaeological artefacts such as mural paintings, mosaics, sculptures and lalariums were rediscovered. This work characterizes two wall mirrors that, together with those recovered from the House of Efebo and the Domus of Euplia, represent the only ones found in the archaeological site of Pompeii. The 2015 and 2016 expeditions of the Analytica Pompeiana Universitatis Vasconicae project performed an in situ multi-analytical study, using only portable non-destructive analytical techniques. Molecular data provided by Raman spectroscopy suggested obsidian was the reflective matrix for both mirrors. Elemental data provided by energy dispersive X-ray fluorescence and laser induced breakdown spectroscopy (LIBS) systems were concordant with Raman spectroscopic results, enabling the detection of Ca, K, Al and Na as the main elements included in the Si matrix characteristic of obsidian igneous rocks. The LIBS data confirmed the presence of obsidian hydration layers. All techniques were used to investigate the degraded white and yellow crusts of the mirrors. Gypsum (CaSO4·2H2O) and nitrocalcite (Ca(NO3)2·4H2O) were identified in the white areas and gypsum and goethite (α-FeOOH) in the yellow crusts. LIBS depth profiling on the white crusts found a layer of nitrocalcite on top of the gypsum layer. Gypsum and goethite were proposed to form after partial dissolution of the mortars patches (with high iron contents) used in modern restorations around the mirrors, followed by a reprecipitation on the surface of the mirrors. Nitrocalcite was proposed to form after the attack of atmospheric NOx on gypsum crusts. These results represent the first analytical work focused on the study of these unique mirrors and provide the knowledge needed for defining more adequate conservation treatments

Multispectroscopic and isotopic ratio analysis to characterize the inorganic binder used on pompeian pink and purple late pigments

International audienc