The relationship between solvent polarity and chromatographic retention (such as Rf values) is a fundamental principle of chromatography and common knowledge in chemistry.
The claim that increasing solvent polarity affects the Rf value or retention in chromatography is a foundational concept in separation science taught universally, making it common knowledge. Retrieved papers such as [3], [4], and [10] discuss mobile-phase elution strength, solvent parameters, and molecular polarity in chromatography, supporting the underlying principles without needing a formal citation to prove the basic premise.