What does the Rf value represent in chromatography?

The Rf value, or retention factor, is defined as the ratio of the distance traveled by a compound (the substance) to the distance traveled by the solvent front. This measurement is critical in chromatography, as it provides a consistent method for identifying substances based on their movement on the chromatography medium relative to the solvent. When analyzing the chromatogram, researchers can calculate the Rf value by measuring how far the substance has traveled from the baseline compared to how far the solvent has moved. This ratio helps in distinguishing different compounds, as each substance typically has a characteristic Rf value under specific conditions, allowing for comparisons and identifications to be made across different samples and experiments.