Chromatography Experiment: Investigating Inks or Pigments in Black Ink

The video discusses the process of chromatography and its application in investigating the inks or pigments in a sample of black ink. The experiment involves using filter paper as the stationary phase and water as the mobile phase. The retention factor or RF value is defined as a ratio of the distance moved by a compound in the solvent to the distance moved by the solvent. The experiment is demonstrated, and after a given time, the distances moved by the solvent and the different pigments are measured to calculate RF values. Different compounds have different RF values in different solvents, and a pure compound will produce a single spot regardless of the solvent used. The video concludes with an example of two chromatograms for the same black ink made using different solvents, revealing different pigments.