Conference Agenda

Heavy metal contamination in rivers is one of the most concerning environmental issues worldwide due to its impact on ecosystems, public health, and national economies. In Mexico, a notable case occurred in 2018 involving the mass mortality of the manatee (Trichechus manatus) in the state of Tabasco, with the municipality of Macuspana being the most affected. This species, classified as endangered under NOM-059-SEMARNAT-2010, inhabits freshwater bodies such as the Bitzal River.

This study aims to investigate the presence of metals and metalloids in the Bitzal River through the analysis of water, sediment, and vegetation samples. Samples were collected at 13 sites in 2018 and at 16 sites in 2024 to determine the concentration of these elements and assess their potential impact on the ecosystem. Comparing both periods allows for the identification of temporal variations in contaminant presence and their possible association with the degradation of the manatee's habitat. Elemental analysis of water, sediment, and vegetation samples was carried out using inductively coupled plasma optical emission spectrometry (ICP-OES) with a PerkinElmer Avio 500 system.

The chemical preparation of water samples involved filtration and subsequent acidification with ultra-high purity nitric acid (HNO₃). For sediment samples, acid digestion was performed using a MILESTONE-MLS microwave digestion system, following the NOM-147-SEMARNAT-SSA1-2004 standard, with a 9:3 mixture of HNO₃ and hydrochloric acid (HCl). Vegetation samples were subjected to microwave-assisted acid digestion using a 9:3 mixture of HNO₃ and hydrogen peroxide (H₂O₂), both of ultra-high purity.

To ensure analytical quality, certified reference materials were used: Montana Soil II NIST® SRM® 2711a for sediments and Certified Reference Material Orchard Leaves (Cat. #CRM-OL) in 4% HNO₃ for vegetation. Data processing and analysis were performed using Syngistix software for ICP. The detection limits achieved by ICP-OES were suitable for assessing compliance with regulatory standards, and recovery rates of reference materials ranged from 80% to 120%.

The results indicate that most metal concentrations in sediment samples from both 2018 and 2024 did not exceed the limits established by current Mexican regulations. However, in the 2024 samples, vanadium (V) exceeded permissible levels at all 16 sampling sites. Furthermore, when compared to international reference values such as the Canadian Environmental Quality Guidelines (CEQG) and the National Oceanic and Atmospheric Administration (NOAA) standards, arsenic (As), nickel (Ni), lead (Pb), and zinc (Zn) exceeded allowable concentrations in all analyzed sites in 2024. The average concentrations of metals and metalloids (mg/kg) in 2018 were as follows: arsenic (As) 17.8 > zinc (Zn) 12.3 > lead (Pb) 5.9 > vanadium (V) 3.4 > nickel (Ni) 1.05. In contrast, significantly higher concentrations were recorded in 2024: vanadium (V) 523.0 > nickel (Ni) 285.5 > zinc (Zn) 117.1 > lead (Pb) 8.2 > arsenic (As) 3.7. In vegetation samples, vanadium (V) was the only quantifiable element.

Statistically, metal concentrations in sediments in 2024 showed a significant increase compared to those from 2018. This rise suggests a possible intensification of contamination, potentially attributable to increased anthropogenic sources, land-use changes, or alterations in local environmental conditions. Regarding water analysis, the average concentrations in 2018 (mg/L) were: arsenic (As) 0.013 > zinc (Zn) 0.011 > nickel (Ni) 0.009 > chromium (Cr) 0.008 > lead (Pb) 0.002. In 2024, the following concentrations were observed: cadmium (Cd) 0.008 > arsenic (As) 0.008 > lead (Pb) 0.008 > chromium (Cr) 0.008 > copper (Cu) 0.007 > nickel (Ni) 0.004 > zinc (Zn) 0.001.

Preliminary conclusions indicate a significant increase in the concentration of elements in water, sediments, and vegetation between 2018 and 2024, particularly for vanadium (V) and nickel (Ni).

The development of oil facilities near natural areas has a significant impact on ecosystems, often serving as sources of heavy metals and metalloids. These substances accumulate in high concentrations, particularly in sediments (Pejman et al., 2015). Mangrove ecosystems act as natural barriers, mitigating erosion and damage caused by storms and hurricanes.

In the study area (Paraiso, Tabasco), an oil refinery was constructed in 2023 and is set to begin operations in 2025. The Aquiles Serdán Ejido, where the mangrove ecosystem is located, lies within the refinery's area of influence. This study aims to assess the current levels of heavy metals and metalloids in sediment samples. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was employed for analysis, coupled with an ultrasonic nebulizer to enhance detection limits.

A total of 90 soil and sediment samples were collected from four distinct zones. Sample preparation involved a Milestone microwave oven, model MLS1200 Ultra, with high-pressure Teflon vessels following the EPA 3051A method. Each sample was digested using 7 mL of nitric acid and 3 mL of hydrochloric acid, then diluted to 50 mL with deionized water. The Montana Soil SRM 2710a was used as the reference material. For the determination of heavy metals and metalloids (As, Cd, Co, Cu, Cr, Ni, Pb, Sb, V, Zn) in sediments, ICP-OES (Avio 500 model, Perkin Elmer®) was utilized. Instrumental conditions included a plasma flow rate of 10 L/min, an auxiliary gas flow rate of 0.2 L/min, and a nebulizer flow rate of 0.5 L/min using an ultrasonic nebulizer (CETAC, model U5000AT+). Detector integration time was set to 10 seconds with three replicates per sample. Detection limits for ICP-OES were 3.2, 0.1, 0.2, 0.5, 0.4, 0.5, 1.9, 1.2, 1.8, and 5.7 μg/L for As, Cd, Co, Cu, Cr, Ni, Pb, Sb, V, and Zn, respectively. Calibration standards included Quality Control Standard 7 and Quality Control Standard Pure 21 from Perkin Elmer®. The recovery percentages of SRM 2711a for As, Cd, Co, Cu, Cr, Ni, Pb, Sb, V, and Zn were 81.04, 88.3, 68.13, 90, 81.62, 91.46, 81.72, 56.38, 63, and 90, respectively. Detection limits achieved using the ultrasonic nebulizer coupled to ICP-OES were superior to those achieved with conventional GemCone nebulizers from Perkin Elmer. The results revealed the presence of Cr (42.66–216.19 mg/kg) as the most abundant element. Other notable elements included vanadium V (36.65–102.37 mg/kg), Zn (42.06–103.87 mg/kg), Ni (13.86–78.20 mg/kg), and Cu (6.84–38.53 mg/kg). Elements found in lower concentrations include As (1.84–2.77 mg/kg), Co (4.74–8.44 mg/kg), and Pb (2.15–8.40 mg/kg). These findings are consistent with the decreasing order of mean concentrations reported by Guo et al. (2023) in mangrove sediments from Dongzhai Harbor, South China. Both studies exhibit similar patterns in the distribution and concentration of heavy metals, particularly Cr and Zn, which could be attributed to comparable anthropogenic influences such as petrochemical and urban industrial activities affecting soil and sediment composition.

1. Pejman, A. H., Bidokhti, A. A., Riahi Bakhtiari, A., & Ardestani, M. (2015). Fractionation of heavy metals in sediments and assessment of their availability risk: A case study in the northwestern Persian Gulf. Marine Pollution Bulletin, 93(1-2), 282-290.

2. Guo, Y., Ke, X., Zhang, J., He, X., Li, Q., & Zhang, Y. (2023). Distribution, Risk Assessment and Source of Heavy Metals in Mangrove Wetland Sediments of Dongzhai Harbor, South China. Int. J. Environ. Res. Public Health 2023, 20, 1090.

The thermal hydrogenation of carbon dioxide (CO₂) to formic acid and other value-added products represents a significant opportunity for sustainable chemical synthesis. Achieving efficient CO₂ conversion and product selectivity, however, critically depends on the development of suitable catalysts [1]. In particular, the design of cost-effective catalytic (nano)materials capable of replacing noble metal-based systems remains a major research focus. In recent years, our group has developed green electrochemical routes for the synthesis of nano- and micro-structured materials, offering a sustainable alternative to conventional wet-chemical and precipitation methods. These electrochemical strategies have demonstrated considerable advantages, including operational simplicity, high yields, and precise control over particle size, morphology, and composition [2].

Among these approaches, sacrificial anode electrolysis in alkaline media has been successfully employed to synthesize Zn-based materials with tunable physicochemical properties. By varying synthetic parameters such as current density and stabilizer composition, we have achieved control over material morphology and phase composition [3]. Here, we report the electrochemical synthesis of (supported) bifunctional Cu/ZnO catalysts using this method. Special attention is given to the role of support materials, specifically zeolites and biopolymeric matrices, which may influence dispersion, stability, and catalytic behavior. The resulting materials have been characterized using a set of advanced spectroscopic and microscopic techniques, including transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and dynamic light scattering (DLS), to elucidate structural, surface, and compositional features. Preliminary catalytic evaluations for CO₂ hydrogenation reactions indicate promising activity and selectivity, underscoring the potential of these electrochemically-derived materials. Comparison with literature-reported catalysts synthesized via conventional routes highlights the advantages of our electrochemical method in terms of environmental sustainability, morphological control, and catalytic performance. This work highlights that electrochemical synthesis is a versatile way for designing next-generation CO₂ hydrogenation catalysts and provides insights into the role of material architecture and support effects on catalytic functionality.

1. M. Aktary et al., Chem. Asian J. 2024, 19, e202301007. doi: 10.1002/asia.202301007.

2. M Izzi et al., ChemElectroChem 2023, 10, e202201132. doi: 10.1002/celc.202201132.

3. M. Izzi et al., ACS Applied Nano Materials 2023, 6, 10881–10902, doi: 10.1021/acsanm.3c01432.

Research funded by European Union - Next Generation EU, Mission 4 Component 1. CUP F93C24000420006 – “MACACO” project.

Integrating photoredox-active and catalytically functional units within a single molecular framework is highly desirable. In this context, bridging ligands that incorporate alkyne groups provide an excellent platform for facilitating efficient photoinduced electron transfer in light-driven catalysis based on ruthenium polypyridyl complexes. However, the inherent reactivity of alkynes under light exposure necessitates strategies to protect these ligands.[1] One promising approach involves embedding the heterodinuclear photocatalyst within a soft-matrix protective macrocycle.

Our focus is to investigate the light-induced multi-electron charge transfer of a Ru–Rh dyad encapsulated within a cucurbit[7]uril ring, forming a novel supramolecular rotaxane photocatalyst. This system is aimed at advancing efficient biomimetic photocatalysis, such as the reductive hydrogenation of NAD⁺. For characterization we employ a set of spectroscopic tools such as time-resolved spectroscopy and resonance Raman spectroelectrochemistry to analyze the light-induced formation and the properties of charge-separated states during multiple electron transfer from the photosensitizer to the catalyst. We pay particular attention to the promising influence of the protective macrocycle with respect to its prevention of potential deactivation pathways.

Acknowledgments

Funding by the Deutsche Forschungsgemeinschaft (German Research Foundation) via the TRR CATALIGHT, Projektnummer 364549901, TRR 234, A1 & C3.

References

[1] Zedler, L., Wintergerst, P., Mengele, A.K., Rau, S. et al., Nat Commun 13, 2538 (2022).

Current quality control techniques in the pharmaceutical industry (e.g. chromatographic methods) require a high amount of organic solvents, are time consuming and do not work with every sample. A greener alternative method is the use of infrared (IR) methods to quantify active ingredients in pharmaceuticals.[1]

In the present study, our team was able to quantify urea in wool alcohols ointment using infrared attenuated total reflection spectroscopy (IR-ATR) in combination with multivariate data analysis, in particular principal components analysis (PCA) and partial least squares regression (PLS-R). Calibration and validation were performed with a total of 108 samples and the PLS-R model was subsequently tested with unknown formulations to proof its reliability.

This approach offers a viable alternative to conduct ring trials usually performed using high performance liquid chromatography (HPLC) methods orchestrated by Central Laboratory of German Pharmacists. HPLC is used despite its high environmental impact, particularly when analyzing lipophilic compounds that require a large amount of organic solvents.[2] In contrast, using the described IR-ATR method, the amount of organic waste is reduced and in general simplifies the sample preparation and is non-destructive.

Furthermore, the low-cost, high-speed, and ease-of-use make this method particularly suitable for in-house quality control in pharmacies, where access to advanced analytical instrumentation is often limited.[3]

The integration of IR-ATR spectroscopy with multivariate data analysis represents a sustainable, accessible, and scalable solution for routine quality control of topical formulations and supports broader adoption of green analytical chemistry principles in pharmaceutical practice.

References:

1. Schlegel, L. B., Schubert-Zsilavecz, M. & Abdel-Tawab, M. Quantification of active ingredients in semi-solid pharmaceutical formulations by near infrared spectroscopy. Journal of Pharmaceutical and Biomedical Analysis 142, 178–189 (2017).

2. Gaber, Y., Törnvall, U., Kumar, M. A., Ali Amin, M. & Hatti-Kaul, R. HPLC-EAT (Environmental Assessment Tool): A tool for profiling safety, health and environmental impacts of liquid chromatography methods. Green Chem. 13, 2021 (2011).

3. Lichtblau, V. & Plener, H. Qualitätssicherung dermatologischer Rezepturen in der Apotheke. Maßgeschneiderte Arzneimittel – patientenfreundlich und sicher. Pharmazie in unserer Zeit 39, 300–305 (2010).

Photochemical vapor generation (PVG) is a highly efficient sample introduction technique increasingly used in analytical atomic spectrometry for determination various elements, including some platinum group metals. However, our understanding of their PVG reaction mechanisms is limited, primarily due to a lack of information about the identities of their volatile species. The majority of the volatile species generated by PVG have been convincingly identified using gas chromatography mass spectrometry (GC-MS), however, this approach has not been successful in identifying the volatile species of Ru, Os, and Ir generated under reductive PVG conditions resulting from UV photolysis of HCOOH, despite their high PVG efficiencies1,2. Regarding their potential volatile species, it can be assumed that UV photolysis of HCOOH media can only produce hydrided/carbonylated metal compounds with the general formula Mx(CO)yHz, provided that the 18-valence electron rule is satisfied.

In this study, a direct analysis in real time (DART) ion source connected to an Orbitrap high-resolution mass spectrometer (HRMS) was used for identification of volatile species of Ir. It was generated using a thin-film flow-through photoreactor and a flow injection (FI) sample introduction from the photochemical media that contained either diluted or concentrated HCOOH, possibly spiked with Co2+, and/or Cd2+ as mediators2,3. The DART-HRMS spectra were recorded in both positive and negative ion modes at a resolution of 120 000 (at 200 m/z). The identification of Ir ions was facilitated by observing a characteristic FI peak profile at any m/z window and characteristic isotopic pattern of Ir (37.3% for 191Ir and 62.7% for 193Ir), and by accurate mass determination.

Initial experiments using nitrogen (N2) as the discharge gas revealed extensive structural transformations within the DART ion source, including notable decarbonylation, hydration, oxidation, and the formation of nitrogen-containing ions. Key parameters, such as discharge gas temperature and transfer tube temperature, were optimized to balance analyte ion sensitivity and minimize structural alteration. Using 10 M HCOOH as the photochemical medium with the addition of 50 mg L–1 Cd2+ as the mediator, the most abundant ions detected in the positive ion mode were [C3H4O6Ir]+ (100%), [C2H4O5Ir]+ (42%), [C3H5O5NIr]+ (42%), and [C2H4O3NIr]+ (23%). Additional ions with lower abundances, such as [C4H2O6Ir]+ (9.2%) and [C4H5O6NIr]+ (6.9%) likely indicate the presence of four CO groups. In the negative ion mode, the most abundant ions were [O2Ir]– (100%), [O3Ir]– (36%), [CH2O2Ir]– (15%), and [C2O3Ir]– (14%). Employing argon (Ar) as the discharge gas reduced fragmentation and oxidation processes, likely due to its "softer" ionization properties, resulting in more straightforward structural characterization, especially in the negative ion mode. Using 0.01 M HCOOH with the addition of 5 mg L–1 Cd2+ as a mediator, the most dominant ions were [O2Ir]– (100%) and [O3Ir]– (60%) again, but these were followed by [C3O3Ir]– (26%), [C2O3Ir]– (11%), and [C4O4Ir]– (6.4%). The latter ion, likely corresponding to Ir(CO)4–, was the one with the highest m/z detected with a significant relative intensity and confirmed that the volatile species was mononuclear Ir carbonyl. With respect to the 18-valence electron for stable transition metal carbonyls, it is reasonable to assume that the volatile species is Ir(CO)4H.

Thus, the DART-HRMS appears capable of identifying some unstable volatile metal carbonyl species, which are difficult to identify using traditional GC-MS techniques and can be used for identification of other unknown volatile species of transition metals generated during PVG.

Reference:

(1) E. Pagliano et al., J. Anal. At. Spectrom. 2022, 37 (3), 528–534.

(2) S. Musil et al., Anal. Chem. 2023, 95 (7), 3694–3702.

(3) E. Jeníková et al., Anal. Chem. 2024, 96 (3), 1241–1250.

Photochemical vapor generation (PVG) under UV irradiation is an emerging sample introduction technique offering enhanced sensitivity and reduced matrix interferences in inductively coupled plasma mass spectrometry (ICP-MS). This study explores the UV-PVG of silver (Ag) and gold (Au) from acidic aqueous solutions, focusing on the nature of the volatile species formed and their efficient transport to the plasma.

Using a low-pressure mercury lamp as the UV source, Ag and Au were exposed to formic acid and other photoreductants to initiate vapor generation. The volatile species generated were directed to ICP-MS for quantitative analysis. Experimental variables such as acid type and concentration, photolysis time, and matrix effects were systematically optimized. The PVG efficiency was found to be highly dependent on the redox chemistry of the metal precursors.

Preliminary evidence suggests the formation of ultra-fine particulate species, possibly metal nanoparticles (NPs), as key carriers in the vapor phase. While the generation of classical molecular species (e.g., hydrides) could not be confirmed for Ag and Au, the volatility and transport efficiency under UV conditions point toward a nanoparticle-mediated mechanism. However, definitive identification of these species remains a subject of ongoing investigation, involving off-line trapping and characterization techniques.

These findings contribute to a deeper understanding of PVG mechanisms for noble metals and support the development of reagent-efficient, green methodologies for trace-level analysis of Ag and Au by ICP MS.

Gastric cancer remains a leading cause of cancer-related mortality, requiring the urgent development of innovative diagnostic tools for early detection. This study presents an integrated infrared spectroscopic electronic nose system, a novel device that combines infrared (IR) spectroscopy and electronic nose (eNose) concepts for analyzing volatile organic compounds (VOCs) in exhaled breath. This system was calibrated using relevant gas mixtures and then tested during a feasibility study involving 26 gastric cancer patients and 32 healthy controls using chemometric analyses to distinguish between exhaled breath profiles. The obtained results demonstrated that the integration of IR spectroscopy and eNose technologies significantly enhanced the accuracy of VOCs fingerprinting via principal component analysis (PCA) and partial least-squares-discriminant analysis (PLS-DA). Distinct differences between the study groups were revealed with an accuracy of prediction of 0.96 in exhaled breath samples. This combined system offers a high sensitivity and specificity and could potetially facilitate rapid on-site testing rendering the technology an accessible option for early screening particularly in underserved populations.

Exhaled breath, which contains gases, volatile organic compounds (VOCs), and aqueous microdroplets, has emerged as a promising matrix for the non -invasive detection of lung diseases, including Covid-19. During the onset or recovery phases of illness, various biochemical processes release gases and VOCs into the bloodstream, which can then diffuse into the lung alveoli and be detected in exhaled breath. A viable strategy for detecting these compounds involves using photoluminescent (PL) materials that respond to VOCs through measurable emission changes.

In this context, we synthesized a novel lanthanide complex, 3NH4[Tb(HPMIDA)2(H2O)] (HPMIDA=desprotonated N-(Phosphonomethyl)iminodiacetic acid), and characterized it with a serie of techniques, among them single-crystal X-ray diffraction. TbHPMIDA exhibits a unique arrangement of phosphonate -OH groups, which could promote effective chemical on the substrate such as commercial SiO2 glass.

Photoluminescence studies demonstrated the material's strong response to specific VOCs, particularly acetone and limonene, which are linked to hyperglycemia (e.g., diabetes) and chronic liver diseases, respectively. The PL intensity showed a linear correlation with VOC concentration, indicating potential for quantitative detection. The interaction between TbHPMIDA and acetone is presumed to occur via reversible hydrogen bonding, as supported by powder X-ray diffraction results.

Successful substrate functionalization was confirmed, and changes in the excitation profiles suggest new interactions between the complex and the substrate. Using a custom gas cell, we evaluated the PL response of the functionalized glass substrate (3 × 3 mm) under acetone exposure, confirming its sensitivity. To further reduce the quantification limits and enhance selectivity, a miniaturized gas cell is being developed. The integration of mid-infrared (MIR) detection in this system could significantly improve molecular discrimination and analytical performance.

Acknowledgements:

Thanks to The São Paulo Research Foundation (FAPESP) for inancial support under grants # 2023/07987-7, 2025/01390-4 and 2021/08111-2. Also thanks to National Council for Scientific and Technological Development (CNPq) for funding this research under grant # 304718/2023-8.

Here we present our latest advancements and achievements in design of fiber optic probes for ultraviolet (UV), visible, near-infrared (NIR), Raman and mid-infrared (MIR) spectroscopy. We developed and tested reflection probes with low straylight and protective window to be used for different applications. These probes specially designed for FTIR and diffraction grating NIR spectrometers.

Robust fiber optic probes enable remote process control at harsh conditions in petrochemical, pharmaceutical and food industries instead of time consuming and expensive sampling which makes process control in-line impossible. Fiber spectroscopy eliminates the need in sample preparation and allows real-time, in-line monitoring of chemical compositions and process parameters, resulting in significant benefits for industrial production due to its increased efficiency, reduced waste, process time, improved product quality and process safety. In particular, fiber optic probes utilizing UV, visible, NIR, and MIR spectroscopy help to detect a wide range of chemical components, making them ideal for the analysis of complex mixtures in different applications: in liquids, powder or even gas media flow. In addition to their ability to monitor processes in real-time and perform measurements in harsh or hazardous environments, fiber-optic probes are lightweight and portable, making them suitable for use in both laboratory and industrial settings. Moreover, combination of several spectroscopic techniques in one combi-probe gives a synergetic effect resulting in better accuracy of measurements. Overall, the adoption of fiber optic probes utilizing UV, visible, NIR, and MIR spectroscopy gives significant advancements in the petrochemicals, pharmaceuticals, foods, and feeds industries, leading to more efficient and cost-effective production processes

The detection of cannabidiol (CBD) at trace levels in complex commercial beverage matrices presents a significant analytical challenge due to molecular interference and signal attenuation. In this study, we employed surface-enhanced infrared absorption (SEIRA) spectroscopy for sensitive and selective identification of CBD in diverse beverage samples including coffee, tea, beer, and sparkling water.

To enhance spectral response, we developed hybrid sensing platforms incorporating chemically reduced graphene oxide (rGO) and compared their performance against commercially available thin (1–4 layers) graphene nanoplatelets. The rGO substrates exhibited notable signal enhancement and high reproducibility. The rGO improved detection capabilities at parts-per-million (ppm) levels surpassing conventional FTIR and commercial graphene-SEIRA performance.

Density Functional Theory (DFT) simulations provided theoretical validation for observed vibrational modes, enabling accurate molecular fingerprinting of CBD. Furthermore, X-ray photoelectron spectroscopy (XPS) was employed to elucidate the enhancement mechanism associated with rGO-CBD interactions.

Our findings confirm the robustness and sensitivity of the proposed rGO-SEIRA platform, offering a promising tool for real-time and non-destructive analysis of CBD in beverages. This versatile approach holds potential for applications in pharmaceutical quality control, forensic analysis, and commercial product authentication.

Laser-based mid-infrared (mid-IR) sensors (e.g., quantum cascade lasers - QCLs) offer high sensitivity and chemical specificity for detecting chemical species in aqueous and marine environments [1–3]. While such systems can readily detect water-soluble inorganic species, monitoring poorly water-soluble organic compounds, such as polycyclic aromatic hydrocarbons and pharmaceutical residues, requires surface enrichment strategies to achieve sufficient sensitivity [4]. Polymer-modified sensing interfaces, particularly in attenuated total reflectance (ATR) and fiber-optic evanescent wave (FEW) configurations, have been widely adopted to enhance the detection sensitivity of such analytes. In this context, thin polymer layers are applied to the sensor waveguide to preconcentrate analytes of interest (AOIs )[5–7].

Although many polymers have been proposed for aqueous and marine applications [4], prolonged water exposure introduces significant challenges, including polymer swelling, water ingress, and morphological degradation, all of which directly impact long-term sensor functionality [8]. In order to use these polymer-based IR sensor types in-field (e.g. marine conditions) within prolonged measurement campaigns (e.g. 30 days or more), the enrichment layers must not only concentrate AOIs effectively, but also maintain spectroscopic integrity under continued aqueous exposure.

In this study, six polymers, including polyisobutylene (PIB), polydimethylsiloxane (PDMS), polyethyleneimine (PEI), polystyrene-co-butadiene (PSCB), poly(acrylonitrile-co-butadiene) (PAB), and poly(methyl methacrylate) (PMMA) were investigated for their swelling behaviour, spectral stability, and morphological resilience. ATR-FTIR spectroscopy was used to monitor in situ spectral changes over a 24-hour immersion of the polymer in Milli-Q and artificial seawater. Swelling was observed in the more hydrophilic polymers, leading to unstable sensor backgrounds in the water vibration region, baseline drift, and a reduced polymer signal after drying, indicative of partial dissolution or detachment of the polymer layer. In contrast, PIB, PSCB, and PAB exhibited minimal water uptake, showed consistent spectral profiles and remained attached on top of the ATR substrate surface.

To asses long-term morphological changes, atomic force microscopy (AFM) [9] was used to characterize polymer-coated silicon wafers before and after immersion for 5, 10 and 30 days in both Milli-Q and seawater. Surface roughness and topographical features were analyzed to quantify film integrity and degradation over water exposure. Initial AFM scans revealed notable coating inhomogeneities: although most surface regions exhibited localized surface elevations between 200 and 900 nm, isolated features reaching up to 4 µm in height were detected for PSCB and PAB, indicating incomplete uniformity during deposition. Upon immersion, PIB and PAB films showed progressive surface degradation, including dissolution of thinner regions and expansion of surface defects. In contrast, PSCB maintained topographical consistency over 30 days, with no significant increase in roughness or evidence of delamination, identifying it as the most morphologically robust polymer film. These experimental observations were further supported by molecular dynamics simulations, which demonstrated that PSCB exhibits the highest resistance to water penetration among the tested polymers.

Combined spectroscopic, morphological, and computational characterization revealed the key degradation mechanisms affecting polymer coatings under prolonged marine exposure and established essential selection criteria for enrichment materials suitable for sustained deployment in laser-based IR sensors targeting particular AOIs.

This work presents a multidisciplinary study combining experimental infrared (IR) fiber-optic sensing and quantum mechanical modeling to optimize the detection of metoprolol in aqueous solution using an AgX optical fiber functionalized with a MOF-808/PVA composite. MOF-808, based on zirconium-oxo clusters and benzene tricarboxylate linkers, was selected for its high porosity and affinity for organic analytes. Its vibrational signature and interaction modes with metoprolol were initially explored using DFT calculations, enabling the identification of key IR-active bands and potential binding configurations. To develop the sensing platform, a 5 cm cylindrical AgX optical fiber (500 µm diameter) was coated with a thin film of MOF-808 dispersed in polyvinyl alcohol (PVA). The PVA matrix served to improve film homogeneity, mechanical adhesion to the fiber, and partial water compatibility, while preserving MOF porosity and enabling diffusion of metoprolol molecules. The functionalized fiber was tested in aqueous metoprolol solutions using quantum cascade laser (QCL) spectroscopy in the 1525–1840 cm-1 range. Despite strong water absorption in this region, pre-processing by water background subtraction and chemometric analysis (PLS regression) allowed the extraction of metoprolol-specific signals. Theoretical calculations support experimental investigation, notably in the aromatic and amide-like vibrational regions. This study aims to establish the synergistic role of MOF-808 and PVA in creating a sensitive and stable fiber-optic IR sensor for pharmaceuticals in water. Parallelly, it also presents a unique way to computationally guide vibrational assignments and interpreting weak or buried signals in complex aqueous environments.

Toxic gases in confined environments like mines pose serious risks to health and safety. We present a compact, portable sensing system for real-time monitoring of hazardous gases (CO, CO₂, CH₄, NO, NO₂, SO₂, H₂S, O₂) using mid-infrared absorption spectroscopy.

The system integrates quantum cascade lasers (QCLs) and substrate-integrated hollow waveguides (iHWGs) for selective, trace-level detection across broad concentration ranges—even where conventional sensors fail. Designed for harsh conditions, it operates reliably under high humidity, dust, vibrations, and electromagnetic interference.

This work is supported by the EU HORIZON 2022 project NETHELIX (No. 101092365).

Green Analytical Chemistry, i.e. the assessment and consideration of environmental, energy and safety aspects, is increasingly becoming part of the overall evaluation of analytical methods [1]. This has led to a new focus on the development and research of improved analytical methods that are more sustainable or 'greener'. Simplified sample preparation such as suspensions and partial digestions for trace element determination by total reflection X-ray fluorescence (TXRF) in various biological samples have been published previously [2,3]. However, matrix- or salt-rich samples such as culture media can affect performance and therefore complicate sample preparation. In this case, sample deposition by nanoliter dispensers can reduce the formation of salt crusts compared to conventionally prepared sample carriers [4].

The aim of this study was the determination of iron and further trace elements in archaea in a simple, green way. First, trace elements in a suspension of Haloferax volcanii H119 in concentrated and diluted nitric acid were quantified by TXRF and successfully validated by solid-sampling high-resolution continuum source graphite furnace atomic absorption spectrometry (SS-HR-CS-GFAAS). Second, conventionally prepared sample carriers were compared with sample carriers prepared using a nanoliter dispenser (M2 Automation, Berlin, Germany). For this purpose, low nanoliters of prepared suspensions were applied in a grid pattern and the resulting analytical figures were compared to sample carriers with a manually pipetted spot of the same total volume. In addition, the greenness of the analytical procedure and sample preparation method was was evaluated using the Analytical Greenness Calculator (AGREE) and the Analytical Greenness Metric for sample preparation (AGREEprep). The greenness evaluation showed a better result for TXRF measurement compared to GFAAS and a better AGREEprep score for suspension in diluted acid compared to concentrated nitric acid.

Light-driven catalytic systems and their molecular components, specifically the photosensitizer and the catalyst, are known to suffer from degradation due to irradiation or harsh reaction conditions. The underlying mechanisms and kinetics are not yet well understood and investigation attempts often rely on invasive, destructive, and ex situ analysis techniques. Previous studies have shown that using in situ multi-spectroscopic analytical platforms with IR-ATR and Raman integration can enable online monitoring of reaction and degradation products with high temporal resolution. However, reaction engineering concepts are not commonly considered during the design of such platforms, which can lead to uncharacterized and unfavorable reaction conditions and consequently, contribute to accelerated system degradation and challenging data comparability. As part of the CataLight CRC/TRR 234 project C2, this work aims to combine reaction engineering and spectroscopic insights to generate high quality reproducible data in order to generate understanding and ensure comparability of different light-driven systems. The focus lies on the development of characterized homogeneous and membrane measurement cells and reactors, optimized for multi-spectroscopic analyses under both batch and flow conditions. Taking functionalized films into consideration, the high temporal resolution is extended by another dimension through additional spatial information via Raman microscopy and µXRF mapping. Generated knowledge on degradation can also give an insight into possible repair and self-regulating mechanisms.

The synthetic cathinone α-pyrrolidinoisohexiophenone (α-PiHP) is among the most frequently detected new psychoactive substances (NPS) in drug seizures across the European Union. Its widespread use and involvement in overdose cases highlight serious public health concerns, yet its metabolic and toxicological profiles remain poorly understood. To address this gap, we employed a multimodal analytical approach integrating live-cell synchrotron radiation Fourier transform infrared spectroscopy (SR-FTIR), Raman spectroscopy, and liquid chromatography–high-resolution tandem mass spectrometry (LC-HRMS/MS) to investigate the metabolic effects of α-PiHP in hepatic cells.

Live HepG2 cells were used for SR-FTIR analysis, fixed HepG2 cells for Raman spectroscopy, and upcyte® human hepatocytes for LC-HRMS/MS profiling of both extracellular media and intracellular content. Vibrational spectroscopy revealed α-PiHP-induced macromolecular alterations in proteins, lipids, and nucleic acids, while LC-HRMS/MS identified perturbations in key metabolic pathways. Multivariate and pathway analyses indicated that α-PiHP shares common metabolic disruptions with other NPS, suggesting potential conserved mechanisms of hepatotoxicity.

This comprehensive strategy enabled a detailed characterization of α-PiHP’s cellular effects, contributing valuable insights for toxicological risk assessment and the development of therapeutic strategies in cases of α-PiHP intoxication.

-