Open Access

Ziel des Projekts war die Entwicklung eines miniaturisierten, siliziumbasierten photonischen Biosensors zur schnellen, empfindlichen und kostengünstigen Detektion klinisch relevanter Herzmarker direkt am Patienten (Point-of-Care). Im Fokus standen zwei Biomarker: das kardiale Troponin I (cTnI) als hochspezifischer Akutmarker des Herzinfarkts sowie das C-reaktive Protein (CRP) als prognostischer Entzündungs- und Risikomarker für Herz-Kreislauf-Erkrankungen. Eine schnelle, quantitative und ortsnahe Messung dieser Marker kann die Diagnose beschleunigen und Behandlungsentscheidungen verbessern. Im Projektverlauf wurden die wesentlichen Bausteine einer solchen Plattform erarbeitet und erstmals zusammengeführt: Die Etablierung von Referenzassays (ELISA) als Vergleichsmaßstab, die Entwicklung der Oberflächenchemie für die Sensorchips, ein kontaktloses Druckverfahren zur präzisen Beschichtung der winzigen Sensorstrukturen sowie erste funktionale Messungen am photonischen Biosensor. Als zentrale Ergebnisse konnten die spezifische Detektion eines Proteins in Echtzeit, die gleichzeitige Mehrkanal-Messung über mehrere Sensoren sowie ein erster Nachweis des Biomarkers CRP am Chip demonstriert werden. Der Transfer auf den anspruchsvolleren Marker Troponin I sowie die Bestimmung belastbarer Nachweisgrenzen bleiben offene, gezielt zu bearbeitende Punkte.

Size Exclusion Chromatography (SEC) remains the most widely applied technique for determining molar mass averages and molar mass distributions of polymers. By separating molecules according to their hydrodynamic volume using a porous stationary phase, SEC provides a chromatogram that, when calibrated with standards of known molar mass, yields a relative molar mass distribution curve. From this curve, key parameters such as number-average molar mass (Mn), weight-average molar mass (Mw), and oligomer content—defined as fractions below 1000 g/mol and 500 g/mol—can be derived. These low-mass fractions are of particular regulatory interest because they represent mobile species with potentially higher bioavailability and toxicity. However, SEC is not without limitations. While error margins of 10–20% for molar mass determination across laboratories and instruments are well documented, variability in oligomer quantification may be even greater. Influencing factors include solvent choice, column configuration, dissolution behaviour, and baseline integration settings. Current DIN and ISO standards, developed from earlier interlaboratory studies, do not adequately address these challenges, especially under conditions relevant to real-life polymer samples. To quantify these uncertainties, a comprehensive round robin test was conducted between June 2024 and February 2025 with 35 laboratories worldwide. Unlike previous studies focused on narrowly dispersed standards, this initiative included complex real-world samples such as copolymers, blends, and dispersions with gel content as a material exhibiting partial solubility. Analyses were performed in three solvent systems (THF, DMAc/DMF, and water) to reflect diverse application scenarios. The results reveal significant interlaboratory variation, particularly in the low molar mass region, with deviations exceeding 50% for Mn and even higher for oligomer content in challenging matrices. These findings underscore the urgent need for harmonized protocols, improved calibration strategies, and clear guidance on solubility and sample preparation. This contribution presents results of the round robin study. Example cases will be discussed and interpreted to allow recommendations for method harmonization. Reducing variability in SEC polymer characterization and increasing the comparability of results are critical steps toward reliable data for regulatory compliance and polymer safety assessment.

This is a corrigendum to the original article "Analysis of carbon and nitrogen from atmospheric sources by bulk deposition sampling at various locations in Germany" that was published in the journal "Environmental advances", vol. 17 (2024), article no. 100583.

Microplastic (MP) analysis relies on complex, multi step analytical workflows in which methodological choices made at early stages directly affect quantitative resu lts. Evidence from the literature indicates that the predominant source of variability stems from insufficient method validation and harmonisation of analytical procedures. MP measurements arise from a sequence of interdependent steps, including sampling, sample pre treatment, extraction and filtration, polymer identification, quantification and data processing. Variations in these steps — such as digestion efficiency, filter retention behaviour, contamination control and spectral parameter selection — systematically lead to non comparable datasets across laboratories and analytical techniques. Without explicit control of these factors, MP data frequently lack cross study consistency, limiting their interpretation in exposure assessment studies and their applicability in regulatory contexts requiring harmonised, validated and traceable measurements. Evidence from interlaboratory and cross technique studies, including comparisons between different IR based systems and Raman spectroscopy, demonstrates that differences in sample preparation, filtration and analytical parameter selection can outweigh instrumental performance in determining MP results. This work presents a workflow oriented framework for MP analysis that identifies critical control points and defines the methodological elements required to control them. For each key analytical step, the role of Standard Operating Procedures (SOPs) in defining operational boundaries is addressed, together with the use of fit for purpose reference materials (RMs) that mimic to assess recovery and performance across the analytical workflow. The implementation of systematic quality assurance and quality control (QA/QC) measures, the establishment of reporting limits (RLs), and the role of interlaboratory comparison studies (ILC) are discussed as essential components for ensuring reproducible, traceable and standardisation MP measurements, providing a practical basis for improving cross‑laboratory and cross‑technique comparability in regulatory‑relevant applications.

Ergotalkaloide (EA) sind toxische sekundäre Stoffwechselprodukte, welche von unterschiedlichen Pilzarten gebildet werden. Aufgrund ihrer toxikologischen Relevanz hat die EU 2022 erstmals Grenzwerte für EA in verschiedenen Lebensmitteln festgelegt. Um diese Grenzwerte zuverlässig zu kontrollieren, sind valide Analyseverfahren erforderlich. In diesem Projekt wurden jetzt erstmals EA-Isotopenstandards hergestellt und erfolgreich in die LC-MS/MS Analytik implementiert.