Development of capillary electrophoresis fingerprint for quality control of rhizoma Smilacis Glabrae

Rhizoma Smilacis Glabrae (RSG) is a Chinese herbal medicine used for detoxication and as a diuretic. However, in some regions of China, RSG is used confusedly with some other herbs.

To develop a capillary electrophoresis (CE)-DAD fingerprint method for quality evaluation, species differentiation and product identification of RSG.

The CE separation conditions and extraction procedure were optimised. Eighteen batches of RSG samples were analysed and the standard fingerprint used for authentication was simulated by the average of all tested samples.

The optimal CE separation conditions were developed with running buffer of 20  mm borax containing 3  mm β-cyclodextrin at pH 9.4, voltage of 25  kV and temperature of 25°C. The separation could be completed within 8  min. Nine peaks were found in the electropherogram of RSG and five peaks were identified as astilbin, taxifolin, 5-O-caffeoylshikimic acid, shikimic acid and trans-resveratrol, respectively. Methanol and sonication were recommended for the sample preparation. All RSG samples showed similar chromatographic profile and six 'held in common' peaks were found. By the standard fingerprint, RSG could be well distinguished from its two confusable species, rhizoma Smilacis Chinae and rhizoma Heterosmilacis.

A CE-DAD fingerprint analysis method was developed for the quality control of RSG. The standard fingerprint could represent the chemical profile of RSG and be used for its authentication.