Analysis of Kakkonto by Nexera-e and SPD-M30A Photodiode Array Detector (Part 1)

Introduction

Kakkonto (traditional Chinese medicine) is believed to be effective against cold, headache, stiff shoulders, etc. because it has the properties to promote sweating and provide anti-inflammatory and analgesic action. It consists of puerariae radix, ephedra, licorice, paeoniae radix, etc. It contains many compounds such as ephedrine, glycyrrhizic acid, and cinnamic acid. The Nexera-e comprehensive two-dimensional liquid chromatograph is useful to separate such a complex sample. In general, different separation modes are selected for 1st and 2nd dimension for comprehensive two- dimensional chromatography. That can enable a high resolution which is not achieved by each individual separation mode. Here, we tried a comprehensive separation by using a semi-micro reversed-phase column and neutral pH mobile phase for 1st dimension and a ultra-high speed reversed-phase column and acidic pH mobile phase for 2nd dimension. Herbal medicines contains many relatively-polar compounds, so pH is said to be important parameter. Glycyrrhizic acid (See the red arrow in Fig. 1) was quantitated.

March 20, 2015 GMT