μ-Raman Spectroscopy Research Articles

Functionalized Cellulose Nanocrystals for Enhanced Wood Protection: Synthesis, Characterization, and Performance

This study developed eco-friendly protective materials for wood preservation, focusing on enhancing fungal decay resistance, insect damage prevention, and improving physical and mechanical properties. The research examined the penetration of cellulose nanocrystals (CNCs) and their functionalized compounds into wood tissue, evaluating their impact on poplar wood. Methodology included optimizing CNC production through acid hydrolysis, testing various temperature and time combinations. CNCs were then functionalized with Poly(dimethylsiloxane)-bis(3-aminopropyl) terminated (PDMS-NH), copper hydroxide, zinc oxide, and silver nanoparticles. Characterization techniques such as AFM, TEM, ESEM, XRD, FTIR, and μ-Raman spectroscopy analyzed CNCs and their derivatives. Wood samples were impregnated with CNCs and functionalized CNCs using pressure and vacuum treatments, then tested for weight gain, durability against white rot (Trametes versicolor) and brown rot (Coniophora puteana) fungi, resistance to insect attack (Trichoferus holosericeus), leaching resistance, and mechanical properties. Key findings included successful optimization of CNC production and functionalization, improved resistance against decay fungi (especially with CNC3/Cu treatment), elevating durability classification from "non-durable" to "low durability". However, treatments showed limited effectiveness against insect infestation. Leaching resistance varied among treatments, with CNC3/PDMS-NH performing best. Mechanical properties, particularly modulus of elasticity, improved significantly with CNC3 impregnation, especially in less degraded wood samples. The study contributes to eco-friendly wood protection systems development, demonstrating functionalized CNCs' potential to enhance wood durability and mechanical properties. Further research is needed to improve insect resistance and optimize the leaching performance of CNC-based treatments, paving the way for more sustainable wood preservation methods.

Microplastic contamination in Indian rice: A comprehensive characterization and health risk assessment

In this study, we investigate, for the first time, the abundance, distribution, chemical composition, and exposure of microplastics (MPs) in Indian rice and their impact on human health. The physical and chemical characteristics of MPs were measured using a stereomicroscope, μ-Fourier transform infrared spectroscopy, and μ-Raman spectroscopy. MPs were identified in all samples, with an average abundance of 30.3 ± 8.61 particles/100 g. The abundance of MPs was higher in RS-4 and lower in RS-3. Notably, the size of MPs found is between <0.05 to 1.00 mm. The results showed that four types of MPs were identified: polyethylene and polyethylene terephthalate were dominant, followed by polypropylene and polyamide. MPs were ubiquitous in all rice sample, indicating ingestion as a potential pathway for the entry of plastics into the human body. According to the pollution load index values, which ranged from 1.00 to 1.528, the contamination of MPs in the rice samples was minimal. The highest estimated daily intake values of MPs from rice consumption by Indian males, females, and children were 1.292, 1.527, and 1.313 particles kg-1 day-1, respectively. Our study sheds light on MP exposure and provides fundamental data for evaluating the potential health risks associated with MPs.

Correlative analysis of advanced microscopy techniques for metallography and corrosion microstructures of bronze phoenician coins

Correlative microscopy stands out for its ability to concurrently acquire and analyze various data types in a multimodal and multiscale environment, enabling precise localization of specific areas within samples and enhancing the accuracy and relevance of analyses. This approach showed promise in revealing the metallurgical history of ancient coins. This article focused on composition, microstructure, and manufacturing process of Phoenician-Punic copper-based alloy coins (5th–4th century BCE). The four coins studied by correlative light and electron microscopy, μ-Raman spectroscopy, and X-ray Microscopy exhibited notable differences in elemental composition and microstructures. These variations are attributed to their origin from casting, followed by striking, and subsequent recrystallization due to a more intricate corrosion process.

Microplastic retention in green walls for nature-based and decentralized greywater treatment

In wastewater treatment, two issues have recently received increased attention: nature-based solutions for addressing urban water stress through decentralized treatment and re-use; and emerging pollutants such as microplastics (MPs). At the interface of these, this study investigated living green walls for greywater treatment and their potential for MP removal.A large, pilot-scale green wall was irrigated with greywater (a mix of water collected from laundry, dishwasher, bathroom sinks, and synthetic greywater), and effluent from planted and unplanted sections was compared. MPs >50 μm were analyzed using μRaman spectroscopy and supplementary fluorescence microscopy imaging. The green wall proved efficient for the reduction of chemical oxygen demand (COD) (around 80%), removal of total suspended solids (TSS) (around 90%) and MPs, especially for MPs of the non-polar, hydrophobic polymer type polystyrene and MPs sized 100–500 μm. MP removal was improved in the planted (50–60%) compared to the unplanted section (20%), especially for the size fraction 100–500 μm. Physical filtration by the green wall growing media (a mix of perlite with a grain size of 1–5 mm, and coconut fiber), which was further enhanced by plant roots decreasing the effective pore size, can be considered the most important removal mechanism. Charge-mediated adsorption cannot be expected as MPs and growing media mix were both negatively charged at the prevailing water pH (7–8). Fluorescence imaging for MP analysis, using a merged UV/blue light fluorograph, overestimated MP concentrations in greywater (hundreds of MPs per sample were identified by fluorescence imaging versus tens of MPs by μRaman spectroscopy) and would benefit from further improvement before it can be reliably applied as a cheaper and faster alternative methodology for MP analysis.

Million Microfiber Releases: Comparing Washable and Disposable Face Masks.

The extensive use of single-use or disposable face masks has raised environmental concerns related to microfiber contamination. In contrast, research on the potential release and ecological impact of microfibers from washable masks (WMs), suggested as an eco-friendly alternative, is currently lacking. Here, we comprehensively investigated the release of microfibers from disposable and WMs of different types in simulated aquatic environments and real-life scenarios, including shaking, disinfection, hand washing, and machine washing. Using a combination of wide-field fluorescence microscopy, He-ion microscopy, and confocal μ-Raman spectroscopy, we revealed that disposable masks (DMs) released microfibers ranging from 18 to 3042 microfiber/piece, whereas WMs released 6.1 × 104-6.7 × 106 microfibers/piece depending on the simulated conditions above. Another noteworthy finding was the observed negative correlation between microfiber release and the proportion of reinforcement (embossing) on the DM surfaces. Microfibers from tested DMs primarily comprised polypropylene (PP), while WMs predominantly released poly(ethylene terephthalate) (PET) and cellulose microfibers. Furthermore, acute toxicological analyses unveiled that PP microfibers (0.01-50 mg/L) from DMs impacted zebrafish larval swimming behavior, while PET microfibers from WMs delayed early-stage zebrafish hatching. This study offers new insights into the source of microfiber contamination and raises concerns about the environmental implications linked to the use of washable face masks.

Unusual spinel in the “Verde Prato” serpentinized peridotite

A petrographic study of “Verde Prato” (trade name of an ophiolitic serpentinised peridotite quarried in Tuscany) revealed, next to a relict Cr-spinel, another opaque ore mineral apparently containing ca.17 wt% SiO2. In order to unveil the origin of this anomalous composition, detailed SEM-EDS, μ-Raman spectroscopy and X-ray μ-diffraction investigations were undertaken, which provided useful but somehow contrasting indications. Therefore, in order to definitely unveil the nature of the unusual opaque mineral, a specific TEM study was undertaken. This showed the presence of submicroscopic euhedral Mn-Cr-Fe-spinels in a matrix of a 7 Å layer-silicate (Al-lizardite). Interesting, all the submicroscopic spinel grains were found to share the same crystallographic orientation, suggesting an origin from a single, larger, former crystal. This unusual type of alteration of the mantle spinel probably occurred on the ocean floor during the pervasive polyphase process of hydrothermal peridotite serpentinization. Overall, by mapping the different serpentinite microstructures and compositions, a polyphase serpentinization history consisting of at least eight different cycles has been suggested. Moreover, the spinel composition indicates that the alteration was accompanied by Mn-metasomatism, made possible by the close proximity of Mn-rich hydrothermal vents, such as “black smokers”.

Methodology Approach for Microplastics Isolation from Samples Containing Sucrose.

The growing production and use of plastics significantly contribute to microplastics (MPs) contamination in the environment. Humans are exposed to MPs primarily through the gastrointestinal route, as these particles are present in beverages and food, e.g., sugar. Effective isolation and identification of MPs from food is essential for their elimination. This study aimed to evaluate factors influencing the isolation of MPs from sucrose solutions to determine optimal conditions for the process. Polyethylene particles were used to test separation methods involving chemical digestion with acids and filtration through membrane filters made of nylon, mixed cellulose ester, and cellulose acetate with pore sizes of 0.8 and 10 µm. The effects of temperature and acid type and its concentration on plastic particles were examined using scanning electron microscopy and µ-Raman spectroscopy. The results indicate that increased temperature reduces solution viscosity and sucrose adherence to MPs' particles, while higher acid concentrations accelerate sucrose hydrolysis. The optimal conditions for MPs' isolation were found to be 5% HCl at 70 °C for 5 min, followed by filtration using an efficient membrane system. These conditions ensure a high recovery and fast filtration without altering MPs' surface properties, providing a reliable basis for further analysis of MPs in food.

Phthalate migration potential in vacuum-packed fish.

Phthalates or phthalate esters (PAEs) have become a serious concern due to their toxicity and risks of migration from contact materials to food matrices and the environment. The aim of this study is to monitor the possible migration potential of PAEs in pelagic fish stored in vacuum packaging depending on the storage time and to determine the polyethylene polymers. In order to achieve this goal, sea bass (Dicentrarchus labrax) and anchovy fish (Engraulis encrasicolus) were randomly packaged in vacuum bags and then stored for 90days. Phthalate content was determined by GC/MS technique in the muscle tissue of each fish species at certain periods (0, 30, and 90days) of storage, and on the first day in the packaging material and fish meat. As a result of the analysis performed in µ-Raman spectroscopy, no microplastics were detected in both fish species' meats. FTIR spectroscopy results of the packaging material determined nylon in the chemical content of the packaging material before processing. It has been determined that the chemical composition of the packaging used in the vacuum packaging process is affected by the temperature, depending on the storage period, and different polymer types are formed in the processed package material. It was determined that the dominant PAE homologues were Di-n-pentyl phthalate (DPENP) in both fish meat and Di-(2-ethylhexyl)-phthalate (DEHP) in the package. However, during storage, Dibutylphthalate (DBP) became dominant in anchovies and DPENP became dominant in sea bass, differing according to fish species and storage time.

Assessment of the Radioactivity, Metals Content and Mineralogy of Granodiorite from Calabria, Southern Italy: A Case Study.

In this paper, an assessment of the natural radioactivity level, radon exhalation, metal contamination, and mineralogy of a granodiorite rock sample from Stilo, in the Calabria region, Southern Italy is presented as a case study. This rock was employed as a building material in the area under study. The specific activity of 226Ra, 232Th and 40K natural radioisotopes was assessed through high-purity germanium (HPGe) gamma-ray spectrometry. Then, several indices such as the absorbed gamma dose rate (D), the annual effective dose equivalent (AEDE), the activity concentration index (ACI) and the alpha index (Iα), were quantified to determine any potential radiological health risk related to radiation exposure from the analyzed rock. Furthermore, E-PERM electret ion chambers and inductively coupled plasma mass spectrometry (ICP-MS) measurements were carried out to properly quantify the radon exhalation rate and any possible metal pollution, respectively. In particular, to further address metal pollution factors, the geo-accumulation index (Igeo) was calculated to properly address the toxicity levels of the ecosystem originating from the detected metals. Finally, with the aim of successfully discriminating the provenance of such naturally occurring radionuclides, a combined approach involving X-ray diffraction (XRD) and µ-Raman spectroscopy was employed for the identification of the main radioisotope-bearing minerals characterizing the investigated granodiorite. The results achieved in this case study can be taken as the basis for further inquiries into background levels of radioactivity and chemical contamination in natural stone employed as building materials.

Distribution, characteristics and ecological risk of microplastics in beach sediments along the Northern coast of Andhra Pradesh, India

Microplastics (MPs) are among the most important emerging contaminants found in marine habitats globally, mandating to comprehend the nature and extent of its pollution in coastal environments before suggesting any mitigation measures. This study aims to investigate the level of MPs contamination in the sediments of 31 beaches along the Northern coast of India's second-longest coastline, the Andhra Pradesh coastline. The sediment samples were analysed to determine the presence of MPs and to investigate their abundance, morphology, spatial distribution, and polymer composition. An aggregate of 346 MP particles were recovered from all the 31 locations by analysing a 20 g sample from each site, with size ranging from 50 to 2000 μm. The average abundance estimated was 564 particles/kg with fibres (89.667 %) as the dominant shape followed by films (8.17 %), fragments (1.88 %) and foam (0.31 %). Transparent, black and blue coloured particles were majorly observed while, other colours identified were brown, red, yellow, pink and green. The predominant polymer type identified by ATR-FTIR and µ-Raman Spectroscopy was polyethylene terephthalate, followed by polypropylene, polystyrene, ethylene vinyl acetate, polyvinyl chloride, and polyester. Further this study also performed a preliminary ecological risk assessment of MPs for the northern Andhra Pradesh coast using PLI and RQ. The PLI computed was >1, indicating pollution. Additionally, 15 of the locations examined have RQ values greater than 1, indicating potential threat to the ecosystem. The findings have provided insights into the risks that can be posed by MPs throughout the Northern coast of Andhra Pradesh, highlighting the absolute necessity of creating effective plans for their control and reduction.

Solid-mechanics analysis and modeling of the alloyed ohmic contact proximity in GaN HEMTs using µRaman spectroscopy

This study explores the impact of alloyed ohmic contact separation on ungated GaN high electron mobility transistors (HEMTs) lattice stress by employing Raman spectroscopy and solid mechanics simulations for comprehensive analysis. Focusing on the substantial stresses exerted by ohmic contacts, our research introduces a novel mechanical calibration procedure. The proposed procedure demonstrates that the stress in the GaN buffer can be precisely modelled using Raman measurements taken from patterns of varying length, which in return reveals the impact of ohmic contacts on stress. We show that this technique shows a good alignment to the Raman measurement results. Moreover, we identify ohmic contact edges as potential sites for defect generation due to the accumulation of substantial elastic energy, a finding supported by experimental observations of crack formations in related studies. Our calibrated mechanical model not only enhances the understanding of stress distributions within GaN HEMTs but also lays the groundwork for future improvements in electro-thermo-mechanical simulations.

Evidence of Correlation between Membrane Phase Transition and Clonogenicity in Dehydrating Acinetobacter baumannii: A Combined Micro-Raman and AFM Study.

The Gram-negative bacterium Acinetobacter baumannii is one of the most resilient multidrug-resistant pathogens in hospitals. Among Gram-negative bacteria, it is particularly resistant to dehydration (anhydrobiosis), and this feature allows A. baumannii to persist in hospital environments for long periods, subjected to unfavorable conditions. We leverage the combination of μ-Raman spectroscopy and atomic force microscopy (AFM) to investigate the anhydrobiotic mechanisms in A. baumannii cells by monitoring the membrane (both inner and outer membranes) properties of four A. baumannii strains during a 16-week dehydration period and in response to temperature excursions. We noted that the membranes of A. baumannii remained intact during the dehydration period despite undergoing a liquid-crystal-to-gel-phase transition, accompanied by changes in the mechanical properties of the membrane. This was evident from the AFM images, which showed the morphology of the bacterial cells alongside modifications of their superficial mechanical properties, and from the alteration in the intensity ratio of μ-Raman features linked to the CH3 and CH2 symmetric stretching modes. Furthermore, employing a universal power law revealed a significant correlation between this ratio and bacterial fitness across all tested strains. Additionally, we subjected dry A. baumannii to a temperature-dependent experiment, the results of which supported the correlation between the Raman ratio and culturability, demonstrating that the phase transition becomes irreversible when A. baumannii cells undergo different temperature cycles. Besides the relevance to the present study, we argue that μ-Raman can be used as a powerful nondestructive tool to assess the health status of bacterial cells based on membrane properties with a relatively high throughput.

Microplastic burden in native (Cambarus appalachiensis) and non-native (Faxonius cristavarius) crayfish along semi-rural and urban streams in southwest Virginia, USA

Our comparative assessment is the first study to investigate microplastic body burden in native (Cambarus appalachiensis) and non-native (Faxonius cristavarius) crayfish along a semi-rural and urban stream across different seasons. Crayfish, sediment, and surface water were collected, processed, and characterized using μRaman spectroscopy to compare microplastic polymer types and shapes across compartments. Average surface water concentrations were significantly higher in our urban stream compared to our semi-rural stream (17.3 ± 2.4 particles/L and 9.9 ± 1.3 particles/L, respectively; P = 0.015). Average sediment concentrations were similar between urban and semi-rural streams (140 ± 14.5 particles/kg and 139 ± 22.5 particles/kg, respectively; P = 0.957). Our findings showed a significant interactive effect of season, site, and nativity (i.e., species) regarding microplastic body burden in crayfish (P = 0.004). The smaller, non-native crayfish amassed more microplastic particles than the native crayfish (0.4–2.0 particles/g versus 0.4–0.8 particles/g, respectively). Fibers and fragments were the most common polymer shapes across compartments, with white and black being the dominant particle colors. Our study identified 13 plastic polymer types in crayfish and three in surface water and sediment; polypropylene was the most common polymer across compartments. This study provides evidence that crayfish body burden of microplastics can differ across species, seasons, and locations, highlighting the need for future studies to consider that sublethal impacts associated with microplastic body burden may vary by region and species.

Distribution and risk assessment of microplastics in water, sediment and brine shrimps in a remote salt lake on the Tibetan Plateau, China

Microplastics (MPs) are pervasive environmental contaminants that have infiltrated even the most remote ecosystems. Despite their widespread distribution, the transfer patterns and impacts of MPs in remote lakes remain poorly understood. This study aimed to address the knowledge gap regarding the pathways and consequences of MP pollution in these isolated environments. Focusing on Kyêbxang Co, a remote salt lake in Tibet, this study investigated the transfer patterns, sources and ecological impacts of MPs, providing insights into their mobility and fate in pristine ecosystems. Water, sediment and biota (brine shrimp) samples from Kyêbxang Co, collected during the summer of 2020, were analyzed using µ-Raman spectroscopy to determine MP abundances, polymer types and potential sources. Findings indicated significant MP contamination in all examined media, with concentrations highlighting the role of runoff in transporting MPs to remote locations. The majority of detected MPs were small fragments (<0.5 mm), constituting over 93 %, with polypropylene being the predominant polymer type. The presence of a halocline may slow the descent of MPs, potentially increasing the exposure and ingestion risk to brine shrimp. Despite the currently low ecological risk estimated for MPs, this study underscores the need for long-term monitoring and development of a comprehensive ecological risk assessment model for MPs.

Developing a quantitative multimodal and multi-scale, fully non-destructive technique for the study of iron archaeological artefacts

This article presents the methodology and initial findings of the SNSF Sinergia project CORINT. The project's objective is to elucidate the corrosion mechanisms affecting iron-based structures entrapped in various porous media. This paper focuses specifically on iron archaeological artefacts (IAAs) in soil. A novel multimodal quantitative imaging technique, which integrates neutron and X-ray computed tomography (NX-CT), is under development for non-destructive examination of corrosion processes. The method involves registering and fusing neutron and X-ray tomography data, followed by Gaussian mixture model (GMM) clustering for phase segmentation. Imaging was conducted on two IAAs, Vrac C and BdC1. Additionally, random cross-sections of these samples underwent analysis through optical microscopy, µRaman spectroscopy, and SEM-EDS to characterize and correlate corrosion layers with NX-CT results. This study yields valuable insights into the corrosion of IAAs, enabling the non-destructive investigation of corrosion processes in porous media. The implications extend beyond the preservation of cultural heritage, to the examination of long-term corrosion behaviors in contemporary iron structures, steel within concrete, and nuclear waste disposal plans.

Preliminary spectroscopic investigation of a potential Mars analog site: Lake Bagno dell’Acqua, Pantelleria, Italy

In this study, we characterize the mineralogy and microbiology of a suite of samples from the Bagno dell’Acqua alkaline (pH ≥ 9) lake in Pantelleria, Italy. The aim of the present characterization is the assessment of the lake as a Martian analog site. Nineteen samples were characterized by a combination of VNIR reflectance spectroscopy, micro-Raman (μ-Raman) spectroscopy, and fluorescence microscopy. In addition, DNA extraction was performed on three selected samples to identify the bacteria phyla and to quantify their abundance. The samples were collected as push cores inside the lake and as loose sediments taken along the eastern and southeastern lake's shore. The samples underwent three thermal cycles (between 343 K and 473 K) to remove excess water and organic matter. The VNIR spectra were measured on each sample after each thermal cycle to check the variation of the spectral features as a function of thermal treatment. The mineralogical content of our push core samples is dominated by the presence of Mg-smectite clays always associated with the remanence of K-feldspars and Ca-carbonates while in the sediments we observe also additional minor phases like pyroxene (aegirine NaFe3+Si2O6), hematite (Fe2O3), anatase (TiO2), and volcanic glass. Two organic phases were detected by μ-Raman spectroscopy. One phase was attributable to carotenoids, in line with the high abundance of Bacterial Phyla that can synthesize these molecules. The second phase appeared to be visually indistinguishable from the inorganic matrix and is therefore attributed to EPS (Extracellular Polymeric Substances) forming a biofilm and extensively observed by fluorescent microscopy. The peculiar chemistry of the waters, the presence of Mg-smectite in the sediments of Lake Bagno dell’Acqua associated with Ca-carbonates and sediments derived by biological activity makes Lake Bagno dell’Acqua a very interesting and promising Martian analog site.

μ-Raman spectroscopy as a useful tool for improving knowledge of ancient ceramic manufacturing technologies

In recent decades, μ-Raman spectroscopy has become a powerful technique for studying ceramics, with the advantage of performing fast, reproducible and reliable analyses that provide effective information on ceramic technology. In the present paper, the potential of μ-Raman spectroscopy was evaluated by comparing the results of spectroscopic analyses with a wide range of conventional compositional and mineralogical analyses. Particular fragments of pottery from the archaeological site of Pollena Trocchia (Campania, Italy), characterized by a variegated color zonation, a symptom of uncontrolled firing conditions, were subjected to in-depth analytical investigation. Data from the μ-Raman measurements were in very good agreement with the analytical set of conventional analyses and permitted to better constrain the firing temperatures, evaluate changes in the oxidative steps, and assert the provenance of volcanic raw materials. The results illuminated that pottery was crafted by mixing a low-CaO base clay with volcanic temper from the environs of Vesuvius and fired in a not well-controlled firing atmosphere, which determined the development of Fe(III) oxides at rims of sherds and Fe(II)-bearing phases at cores. Moreover, even in the absence of newly-formed minerals, firing temperatures were estimated between 900 and 950 °C, as suggested by the mineralogical and spectroscopic evidence of the prograde 10 Å dehydroxylated phyllosilicates.

Evaluation of phthalate migration potential in vacuum-packed

In recent years, the presence and migration of PAEs in packaging materials and consumer products has become a serious concern. Based on this concern, the aim of our study is to determine the possible migration potential and speed of PAEs in benthic fish stored in vacuum packaging, as well as to monitor the storage time and type as well as polyethylene (PE) polymer detection.As a result of the analysis performed by µ-Raman spectroscopy, 1 microplastic (MP) of 6 µm in size was determined on the 30th day of storage in whiting fish muscle and the polymer type was found to be Polyethylene (PE) (low density polyethylene: LDPE). Depending on the storage time of the packaging used in the vacuum packaging process, it has been determined that its chemical composition is affected by temperature and different types of polymers are formed. 10 types of PAEs were identified in the packaging material and stored flesh fish: DIBP, DBP, DPENP, DHEXP, BBP, DEHP, DCHP, DNOP, DINP and DDP. While the most dominant PAEs in the packaging material were determined as DEHP, the most dominant PAEs in fish meat were recorded as BBP and the lowest as DMP. The findings provide a motivating model for monitoring the presence and migration of PAEs in foods, while filling an important gap in maintaining a safe food chain.

Characterization of Tableware from Fábrica de Loiça de Sacavém—Linking Analytical and Documental Research

Fábrica de Loiça de Sacavém (ca. 1858–1994) was among the first to produce white earthenware in Portugal, becoming one of the country’s leading ceramic manufacturers during the late 19th to early 20th centuries. Research on white earthenware has accompanied the growing interest in post-industrial archaeology but is still poorly explored compared to more ancient ceramic productions. This study focused on the ceramic body, glazes, and colourants of tableware produced by Fábrica de Loiça de Sacavém during the first 50 years of its activity (1859–1910). A multi-analytical approach was selected to investigate the chemical and mineralogical composition of the ceramic body, glaze, and pigments using optical microscopy, variable-pressure scanning electron microscope energy-dispersive X-ray spectroscopy (VP-SEM-EDS), μ-Raman spectroscopy, μ-X-ray Diffraction (μ-XRD), and reflectance spectroscopy (hyperspectral image analysis). The studied tableware was produced with a Ca-poor siliceous–aluminous white earthenware ceramic body covered with transparent alkali lead or lead borosilicate glaze, and most colourants were complex Cr-based pigments. These results are in agreement with the little documental evidence from this period found in the manufacturer’s archives.

Identification of Microplastics Using µ-Raman Spectroscopy in Surface and Groundwater Bodies of SE Attica, Greece

Sixteen surface (5) and groundwater (11) samples were collected from the south-eastern part of Attica, Greece, and analysed for physico-chemical parameters and microplastics (MPs) by optical microscopy and Raman microspectroscopy (RS). A total of 3399 particles were optically identified in all sixteen samples, ranging from only 16 particles/L in a sample from a deeper borehole to 513 particles/L in a sample from a shallow water well. They were then visually classified into eight categories based on their color, texture, size, reflectivity, shape, and general morphological properties. Raman microspectroscopy was performed on the particles on the filters and revealed four different types of MPs, namely polyethylene (PE, 35%), polypropylene (PP, 30%), polystyrene (PS, 10%), and polyethylene terephthalate (PET, 25%). The samples from the shallow phreatic aquifer contained more MPs than the samples from the deeper borehole, which contained fewer MPs and categories. This is to be expected, since the phreatic aquifer (a) is generally more contaminated, as it is close to human activities that generate MPs and its infiltration depth is only a few metres, which means that many microplastics can infiltrate at such shallow depths, and (b) it is exposed to the atmosphere, so they can also be suspended in the air. On the other hand, it is interesting to note that MPs, especially PET and PE, were detected in the borehole sample, suggesting that MPs can migrate to greater depths through water infiltration. Chemical analyses of the groundwater samples revealed high values of E.C., Ca2+, Mg2+, Cl−, and Na+, which indicate that seawater intrusion is taking place in the coastal aquifer system of the Erasinos basin. The increased concentrations of NO3− and PO43− also indicate the impact of agricultural activities.