Botanical Information Dioscorea oppositifolia L. (procuring samples)
| Synonyms | Dioscorea opposita Thunb. |
| Dioscorea oppositifolia var. dukhunensis Prain & Burkill | |
| Dioscorea oppositifolia var. linnaei Prain & Burkill | |
| Dioscorea oppositifolia var. thwaitesii Prain & Burkill | |
| Common name (en) | Common yam |
| Sample preparation | To 0.5 g of the powdered herbal drug add 5 mL of methanol. Sonicate for 10 min. Centrifuge and use the supernatant |
| Mobile phase | Water, methanol, methylene chloride 8:40:52 (v/v/v) |
| Derivatization | Treat with anisaldehyde solution, heat at 100 °C for 3 min, allow to cool for 10 min and examine |
| Sample preparation | To 2 g of the powder, add 30 mL of dichloromethane, heat under reflux for 2 h and filter. Evaporate the filtrate to dryness, dissolve the residue in 1 mL of dichloromethane as the test solution |
| Mobile phase | Ethyl acetate, methanol, ammonia 9:1:0.5 (v/v/v |
| Derivatization | Spray with 10% solution of phosphomolybdic acid in ethanol, heat at 105°C until the spots appear |
| Sample preparation | Add 5.0 g of powdered sample to 30 mL of dichloromethane, heat under reflux for 2 h and filter, evaporate to dryness, dissolve the residue in 1 mL of dichloromethane |
| Mobile phase | Ethyl acetate, methanol, concentrated ammonia solution 9:1:0.5 (v/v/v) |
| Derivatization | Spray with a 10% solution of phosphomolybdic acid in ethanol and heat at 105°C until the spots appear |