[An orthogonal method for comparing extracting techniques of licorice root extract].

A L9(3(4)) form developed by the orthogonal method was used to study the size, extraction solvent and extraction frequency of licorice root extract, and taking the recovery of glycyrrhizic acid as the criteria, a comparison was made on the different ways of extracting the herb. The result showed the glycyrrhizic acid could be recovered over 10% (about 7% higher than that from water treatment) when the herb was cut into pieces and then extracted by fluxing for 3 times with 60% alcohol containing 0.3% ammonia.