Redox titration using cerium(IV), in which an iron(II)-1,10-phenanthroline complex (ferroin) color change indicates the end-point.
Source:
PAC, 2025, 97, 137. 'Glossary of terms for mass and volume in analytical chemistry (IUPAC Recommendations 2024)' on page 2 (https://doi.org/10.1515/pac-2023-0903)