Establishment of Thin Layer Chromatography Identification Method for Different Processed Products of Rehmanniae Radix / 中国实验方剂学杂志

ABSTRACT

Objective:To establish a thin layer chromatography （TLC） identification method for different processed products of Rehmanniae Radix. Method:Catalpol， D-fructose， sucrose， raffinose， stachyose， melibiose and manninotriose were used as control substances， and the effects of extraction solvents （water， 20% methanol， 50% methanol， 80% methanol）， developing solvents （n-butanol-methanol-chloroform-glacial acetic acid-water， ethyl acetate-pyridine-glacial acetic acid-water， n-butanol-glacial acetic acid-water）， color reagents （aniline-diphenylamine-phosphoric acid solution， ninhydrin solution）， sampling volumes （2， 4， 6 μL） and inspection conditions （sunlight， bottom lamp of sunlight， 365 nm， 254 nm） on TLC were investigated to determine the preparation method of sample solution of Rehmanniae Radix and Rehmanniae Radix Praeparata and the optimal TLC conditions. Result:High performance silica gel G plate was used for TLC， n-butanol-methanol-chloroform-glacial acetic acid-water （13∶5∶5∶1∶2） was used as developing agent， aniline-diphenylamine-phosphoric acid solution was sprayed and heated at 110 ℃ for color development， and then inspected under the bottom lamp of sunlight. The separation and color development of different processed products of Rehmanniae Radix were good with clear spots and good characteristics. Conclusion:The established TLC is simple and easy to operate with obvious qualitative characteristics and intuitive results. It can effectively identify different processed products of Rehmanniae Radix and provide experimental basis for determining the end point of processing of Rehmanniae Radix Praeparata.