Microwave Assisted Extraction of Curcumin from Curcuma Longa L. by Ionic Liquid Bi-aqueous Phase System

Microwave assisted extraction was applied to the separation of curcumin from curcuma longa L, in a bi-aqueous phase system containing ionic liquid of N-butylpyridine bromide (abbr. as ［BPy］Br) and K2HPO4. Its absorbance was measured at the ware length of 424.5 nm a UV spectrophotometric method for determination of the content of total curcumin was proposed. The optimum conditions of extraction were tested by the orthogonal experiment and the results found were as follows: ① mass ratio of sample to liquid: 0.015 to 1; ② microwave power: 320 W; ③ time of extraction: 120 s; and ④ amount of K2HPO4 added: 7.0 g. Under the optimized conditions, extraction rate of curcumin attained to a value of 4.99% which was more than 100 times higher than the extraction rate (0.042%) obtained by the conventional heat-reflux-extraction method.