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Dubravka Božić, Biserka Runje, Andrej Razumić
Risk Assessment for Calibration: The Non-Linearized Case

This study presents a novel mathematical model designed to evaluate risks in calibration processes. A probabilistic model was described for estimating the global producers' and consumers' risk with a non-linearized tolerance interval. The measurement uncertainty required to assess the risk for the explanatory variable at a given value of the response variable was calculated from the regression analysis outcome. The model was tested on the example from industrial practice to evaluate the risks associated with calibrating the roundness measurement device within a moderate scale of -3 μm to 3 μm. The results indicate that global consumer and producer risks are lower in the non-linear model than in the linear model. The calibration risk assessment model was evaluated using confusion matrix-based metrics.

Abigail Grace Bion, Aaron Dacuya, Alleni Junsay, Benilda Ebarvia
Development and Validation of Reliable Quantitative Methods for Ethoxyquin in Chicken by Fluorescence Detection (LC-FLD) and Isotope Dilution Tandem Mass Spectrometry (LC-IDMS/MS)

Ethoxyquin (EQ), a quinoline-based antioxidant, is widely used in food and animal feed, often leading to residues in animal tissues—raising health concerns. This study developed and validated two quantification methods: liquid chromatography with fluorescence detection (LC-FLD) and isotope dilution tandem mass spectrometry (LC-IDMS/MS). Sample preparation employed the QuEChERS technique with enhanced matrix removal-lipid (dSPE EMR-lipid). The LODs/LOQs were 2.4/3.6 μg/kg (LC-FLD) and 1.7/2.5 μg/kg (LC-IDMS/MS). Both methods showed excellent linearity (R = 0.999) using matrix-matched calibration. Recoveries at three spiking levels ranged from 94% to 106%, while repeatability (RSD ≤ 4.2%, n = 10) and intermediate precision over one, two, and three month period (RSD ≤ 7.6%, n = 3) complied with Horwitz criteria. The methods proved suitable for reliable EQ monitoring in chicken and similar matrices and were fit-for-purpose for homogeneity and stability studies and reference value assignment of a chicken-based reference material.

Clarissa Manguin, Ian Deniell Magsino, Janesky Esplana, Alleni Junsay
Validation of Analytical Methods for Assessing Heavy Metal in Green Mussels (Perna viridis) from Major Mussel-Producing Regions in the Philippines

Green mussels (Perna viridis) are an important marine resource in the Philippines, widely farmed for their economic and nutritional value. As filter feeders, they can accumulate heavy metals like cadmium (Cd), mercury (Hg), and lead (Pb), posing potential health risks. This study developed and validated gravimetric external calibration methods to quantify heavy metal levels in mussels from major producing regions using Graphite Furnace - Atomic Absorption Spectrophotometry (GF-AAS) for Cd and Pb, and Direct Mercury Analyzer (DMA) for Hg. Validation showed strong linearity (r > 0.995), with LOQs of 20.9 μg/kg (Hg), 175.9 μg/kg (Cd), and 208.7 μg/kg (Pb). Trueness was confirmed using NIST SRM for Oyster Tissue and spike recovery, with acceptable recovery ranges of 85 – 105 %. Measurement results revealed Hg and Pb levels in mussels were below regulatory limits, while Cd exceeded limits in one region. These methods support food safety monitoring and quality assurance in Philippine aquaculture.

Alleni Junsay, Clarissa Manguin, Ian Deniell Magsino, Janesky Esplana, Gian Ernest Dizon, Aaron Dacuya
Proficiency Testing Scheme for Toxic Elements in Milkfish (Chanos chanos) in the Philippines: Ensuring Food Safety and Quality Control

Milkfish (Chanos chanos) is a staple
aquaculture product in the Philippines, making food
safety and quality assurance essential for consumer
protection. This study presents an accuracy-based
proficiency testing (PT) scheme to assess the capability
of Philippine chemical testing laboratories to quantify
toxic elements in milkfish. Philippine Reference
Material (PRM) 2002 – As, Cd, Hg & Pb in Milkfish
was prepared and distributed to participating
laboratories for independent analysis. Results were
evaluated using z’-scores and other statistical
performance metrics.
A total of 26 local testing laboratories participated in
the PT scheme, with 23 submitting results. Among
them, 42 % of the 12 participants for total As, 62 % of
the 21 participants for Cd, 64 % of the 14 participants
for total Hg, and 82 % of the 22 participants for Pb
achieved an "acceptable" z’-score performance. These
findings highlight areas for improvement in laboratory
proficiency, underscoring the importance of
continuous development and active participation in
accuracy-based proficiency testing (PT) schemes to
enhance the reliability and accuracy of toxic element
analysis in Philippine laboratories.

Francesca Durbiano, Francesca Rolle, Francesca Pennecchi, Stefano Pavarelli, Ramona Russo, Chiara Festevole, Michela Sega
Cavity ring-down spectroscopy for the certification of the isotopic composition of CO2 in air CRMs

Carbon dioxide (CO2) is the most important long-lived anthropogenic greenhouse gas. Studying the ratio 13C/12C of the CO2 isotopic composition (δ13C-CO2) in the atmosphere gives useful information for assessing and quantifying the anthropogenic contribution to the continuously growing atmospheric CO2. INRiM, the Italian National Metrology Institute, is deeply involved in supporting the efforts of the metrological community to achieve the comparability of results and to assure accuracy and metrological traceability to CO2 stable isotope measurement results. In this framework, the realization of gaseous reference materials of CO2 in air at ambient level and known δ13C-CO2 represents a fundamental and promising activity. This work describes the preparation of the gas mixtures with δ13C-CO2 values in the range from +1.3 ‰ to -42 ‰ and the analytical procedure for the value assignment based on Cavity Ring-Down Spectroscopy. Preliminary stability studies are also shown.

Michela Sega, Francesca Rolle, Francesca Durbiano, Stefano Pavarelli, Francesca Romana Pennecchi, Ramona Russo, Chiara Festevole
Metrological traceability paths for stable isotope measurements of CO2 in air

Measurements of carbon stable isotopes 13C and 12C and of their ratio 13C/12C in atmospheric carbon dioxide (δ13C-CO2) are indicators of the anthropogenic contribution to CO2 emissions. At present, δ13C-CO2 falls within the CIPM MRA traceability exception. Gaseous Certified Reference Materials (CRMs) are needed as proper references to support the scientific community dealing with δ13C-CO2 in atmospheric measurements. The paper presents an approach to assign δ13C-CO2 values to CO2 gas mixtures at atmospheric amount fraction following two independent traceability paths, leading to candidate CRMs with established metrological traceability to the Vienna Pee Dee Belemnite scale, which represents an international recognized primary scale in this framework. INRiM is working towards the attainment of internationally recognized Calibration and Measurement Capabilities in the CIPM MRA framework for the production of such CRMs, which represents a fundamental step to meet the increasing demand of proper references for stable carbon isotopes measurements in atmosphere.

Mary Joy Bautista, Morris Pioquinto, Jo Marie Venus Agad, Gina Catalan
Rapid Monitoring of Key Alloying Elements in Deformed Steel Bars Using Portable EDXRF and LIBS: A Strategy Against Substandard Quality

This study investigates the effectiveness of combining portable analytical techniques - Energy Dispersive X-ray Fluorescence (EDXRF) and Laser-Induced Breakdown Spectroscopy (LIBS) - as alternatives to traditional Spark Optical Emission Spectroscopy (Spark-OES) for the rapid assessment of key alloying elements Carbon (C), Silicon (Si), Manganese (Mn), Phosphorous (P) and Sulfur (S) in deformed steel bars. Both EDXRF and LIBS demonstrated strong accuracy and precision in analyzing C, Si, and Mn, with statistical analysis revealing significant correlations with the Spark-OES benchmark. However, detection of P and S requires further optimization due to inherent analytical challenges. The combination of these portable methods offers substantial advantages, including on-site testing capabilities and minimal sample preparation, enabling real-time monitoring and immediate quality control. The findings underscore the potential of EDXRF and LIBS to enhance quality assurance processes in the steel industry, promoting safer construction practices through efficient, non-destructive testing methods.

Andrea Bergomi, Paola Fermo, Chiara Lombardi, Michela Pirovano, Antonino Fiorentino, Mattia Borelli, Mario Colella, Valeria Comite
Surface Features of the Giovanni Rasori marble monument (1840, Milan): chemical characterization of degradation and past restoration interventions

The conservation of outdoor heritage in urban environments requires careful analysis of degradation processes induced by atmospheric pollutants. This study presents the results of a scientific investigation on the marble monument of Giovanni Rasori (1840), located in Milan, a city affected by heavy traffic and industrial emissions. Exposed for decades to an outdoor polluted environment, the monument exhibited visible signs of surface alteration. Analytical techniques, including SEM-EDX and ATR/FTIR, revealed that the primary degradation process was sulfation, confirmed by the presence of gypsum on the marble substrate. Moreover, the detection of Ti in localized areas of certain micro-fragments suggests the possible use of a whitening agent or pigment during past restoration works. Additionally, the co-presence of elements such as Si, Al, and Fe may be linked to atmospheric dust or to abrasive residues from earlier cleaning practices, such as micro-sandblasting, historically used in stone conservation. These findings contribute to a deeper understanding of marble surface transformations in polluted urban contexts.

Nicolò Di Marco, Elvia Maria Letizia Giudice, Filippo Stanco
Virtual Reconstruction of the Temple of Olympian Zeus in Syracuse: A Journey in the Metaverse between History and Technology

This paper presents the results of a research that led to the virtual reconstruction of the Temple of Olympian Zeus of Syracuse within the metaverse. Through the integration of traditional archaeological methodologies and advanced digital technologies, the project offers an immersive experience that allows to explore one of the most significant monuments of Magna Graecia. The paper illustrates the methodological process adopted, the technical challenges faced and the educational and dissemination potential of this approach in the context of the valorization of historical-cultural heritage. Also, through Virtual Reality it is possible to visit the implemented metaverse, using Meta Quest VR headset.

Paola Fermo, Valeria Comite, Chiara Andrea Lombardi, Mattia Borelli, Andrea Bergomi, Giulia Galli, Gianluca Carabelli, Daniele Bolleri, Letizia Bonizzoni, Francesca Sabatini
Preliminary findings from a non-invasive and micro-invasive multi-analytical study of the painting “Posa della Prima Pietra” by Ismaele Teglio Milla (1853)

A preliminary investigation into the painting technique and colour palette used in the “Posa della Prima Pietra” canvas by Ismaele Teglio Milla (1853) was carried out in this study. The main goal was to evaluate the presence of preparatory drawings or pentimenti and to spectroscopically characterize the materials used in the artwork. For these purposes, a micro- and non-invasive multi-analytical approach was employed using the following techniques: Multi-Spectral Imaging (MSI), portable X-Ray Fluorescence (XRF), Scanning Electron Microscopy with Energy Dispersive X-ray spectroscopy (SEM-EDX), Attenuated Total Reflection Fourier-Transform Infrared spectroscopy (ATR-FTIR) and Visible Reflectance Spectroscopy (Vis-RS). The results highlighted several pentimenti and other changes made by the artist, along with the identification of most of the colour palette and the components of the preparatory layer.

Page 5 of 977 Results 41 - 50 of 9762