TLC Purity

Thin-layer chromatography purity assessment provides a rapid, low-cost, qualitative-to-semiquantitative purity check, in which a single, clean spot at the...

Thin-layer chromatography purity assessment provides a rapid, low-cost, qualitative-to-semiquantitative purity check, in which a single, clean spot at the expected retardation factor under both short- and long-wavelength ultraviolet light, without any additional visible spot corresponding to starting material or an obvious degradation product, provides preliminary reassurance of compound purity ahead of more definitive HPLC analysis. TLC purity assessment is most valuable as an in-process monitoring tool during synthesis and purification — confirming that a chromatographic or recrystallization purification step has successfully removed a specific known impurity — rather than as a final, regulatorily reportable purity determination, a role reserved for the more sensitive and genuinely quantitative HPLC method.