In February 2026, Ms. Anastasia Edsell, a graduate student in analytical chemistry at the University of Amsterdam (the Netherlands), visited our laboratory. During her visit, we exchanged ideas on source apportionment using stable isotope ratio analysis, LC-IRMS and LC-HRMS (Orbitrap) approaches for water-soluble and polar compounds, and challenges related to the development and standardization of isotope reference materials. This visit provided a valuable opportunity for international academic exchange.