In this review, we report and critically discuss the application of LIBS for the determination of plasma-emission fundamental parameters, such as transition probabilities, oscillator strengths, Stark broadening and shifts, of the emission lines in the spectrum. The knowledge of these parameters is of paramount importance for plasma diagnostics or for quantitative analysis using calibration-free LIBS methods. In the first part, the theoretical basis of the analysis is laid down; in the second part, the main experimental and analytical approaches for the determination by LIBS of the spectral line spectroscopic parameters are presented. In the conclusion, the future perspectives of this kind of analysis are discussed.
The rapid identification of beached marine micro-plastics is essential for the determination of the source of pollution and for planning the most effective strategies for remediation. In this paper, we present the results obtained by applying the laser-induced breakdown spectroscopy (LIBS) technique on a large sample of different kinds of plastics that can be found in a marine environment. The use of chemometric analytical tools allowed a rapid classification of the pellets with an accuracy greater than 80%. The LIBS spectrum and statistical tests proved their worth to quickly identify polymers, and in particular, to distinguish C-O from C-C backbone pellets, and PE from PP ones. In addition, the PCA analysis revealed a correlation between appearance (surface pellets roughness) and color (yellowing), as reported by other recent studies. The preliminary results on the analysis of metals accumulated on the surface of the pellets are also reported. The implication of these results is discussed in view of the possibility of frequent monitoring of the marine plastic pollution on the seacoast.
Although approximately half of global lithium consumption is used in the rechargeable battery industry, lithium is also in demand for other specialized applications, such as high-temperature lubricants, ceramics, glass, and pharmaceuticals. The growing need for efficient lithium recovery and recycling underscores the importance of fast and accurate analytical tools for determining lithium concentrations in non-compliant and waste materials generated by industrial processes. In this paper, we present a machine learning-based procedure utilizing Laser-Induced Breakdown Spectroscopy (LIBS) to accurately quantify lithium concentrations in lithium-rich non-compliant materials derived from the industrial production of enamels used for coating metallic surfaces. This procedure addresses challenges such as strong self-absorption and matrix effects, which limit the effectiveness of conventional univariate calibration methods. By employing a multivariate approach, we developed a single model capable of quantifying lithium content across a wide concentration range. A comparison of the LIBS results with those obtained using conventional laboratory analysis (Inductively Coupled Plasma–Optical Emission Spectrometry, ICP-OES) confirms that LIBS can deliver the speed, precision, and reliability required for potential routine applications in the lithium recovery and recycling industry.
Enrico Van Lint (Pisa, 1808–1884) was a very prolific photographer, active in Pisa in the 19th century where he had a prominent photographic atelier. He was a meticulous experimenter, investigating the evolving photographic activity of his historical period. While his early works included calotypes using Fox Talbot’s methods, he rapidly adopted the collodion processes, becoming one of the most important Italian photographers that used this technique. At the present time, a vast number of examples of the works from Van Lint’s ateliers are preserved and archived in Pisa, under the supervision of the Italian Ministry of Culture in the Photographic Archive of the “Soprintendenza Archeologia, Belle Arti e Paesaggio per le provincie di Pisa e Livorno” (SABAP). This collection is composed of positive prints as well as glass plate negatives, from both Van Lint himself and his colleagues. To this day, Van Lint’s collection has not been studied using analytical techniques, and the identification of the photographic processes involved in the preparation of the positive prints has relied exclusively on thorough observation by historians and conservators. This provides a unique occasion for a first study of Van Lint’s collection, using multiple non-invasive and non-destructive techniques (multispectral imaging, XRF, and FTIR) that can identify the photographic process used to make the positives, as well as highlight significant differences or degradation phenomena. In this preliminary work, we investigated a selection of ten positive prints, attributed to both Van Lint himself and later reproductions from the original glass negatives. The selected samples include prints previously classified as albumen prints and gelatin prints, displaying slight differences in conservation status as well as in print finish. This analytical approach allowed for a proper characterization of these Van Lint’s prints, improving the historical and conservation knowledge to implement the best preventive preservation actions in the near future.
Several samples coming from the recently discovered (February 2019) Late Bronze Age/Early Iron Age Chovdar necropolis in Azerbaijan were analysed using the X-ray fluorescence (XRF) technique. The analysis allowed a preliminary classification of the samples in eight groups based on their composition, obtained from the XRF spectra using the fundamental parameter method. A more detailed classification was then obtained using the graph clustering method.
Plastic pellets represent a significant threat to marine environments: beyond being pollutants themselves, they can act as vectors for other contaminants by absorbing organic pollutants and metals. In this study, synchrotron-based micro-X-ray fluorescence (micro-XRF) mapping was applied to spatially resolve heavy and trace metal distributions in environmental polyethylene pellets collected along the Tyrrhenian coast. By analyzing pellets exhibiting different degrees of yellowing and biofouling, the study explores the relationship between environmental exposure parameters and metal accumulation. The results distinguish surface-associated metals related to adsorption and biofouling from metals penetrating the polymer interior, particularly in aged pellets. This spatially resolved approach provides new insight into metal accumulation mechanisms and the associated environmental impact and potential risk to human health linked to plastic pellets.