RESUMO
Objective To study the method for distinguishing the crude and processed Radix of Polygonum multiflorum Thunb. by TLC. Methods Some of the samples were collected from different cities in China, some of them were prepared following the pharmacopoeia standard or local standard. TLC conditions: 5-hydroxymethyl-furfural (5-HMF) was used as a standard matter with the developing solvent of petroleum ether (60～90 ℃)-ethyl acetate (1∶1) on a silica G thin layer plate, sprayed with 15% ?-naphthol in ethanol solvent, heated and detected in daylight. Results TLC chromatogram showed that crude and processed product of Polygonum multiflorum Thunb. were different. Conclusion TLC method for distinguishing the crude and processed Polygonum multiflorum Thunb. was established.