7-Hydroxyquinoline-8-carboxylic acid is primarily used in analytical chemistry as a chelating agent. It forms stable complexes with various metal ions, making it valuable for the detection and quantification of metals in solutions. This compound is particularly effective in spectrophotometric analysis, where it aids in the precise measurement of metal concentrations due to its strong binding affinity. Additionally, it is employed in research settings for studying metal-ligand interactions and in the development of new analytical methods for metal ion determination. Its ability to selectively bind specific metals also makes it useful in environmental monitoring, where it helps in assessing metal pollution levels in water and soil samples.