In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

Results of this technique for organic molecules can be used to calculate the Kovats index. The molar mass distribution of polymers can be found with the size-exclusion type of this technique. The retention factor of this technique can be calculated as the migration distance of the analyte divided by the migration distance of the solvent. Pigments can be analyzed in the "paper" type of this technique, which also comes in high-performance liquid and "thin layer" types. For 10 points, name this chemical technique that separates mixtures based on polarity.
Science