[Study on double fingerprints of isatidis radix micropowder]

To establish the double HPLC fingerprints of water-soluble composition and amino acids precolumn derivative reagent of 13 batches of Isatidis Radix micropower.

The gradient elution was adopted with Hypersil BDS C18 column (4.6 mm x 250 mm, 5 microm). Water-soluble ingredients were detected with acetonitrile-0.1% phosphoric acid solution as mobile phase, flow rate 0.5 mL x min(-1), column temperature 20 degrees C, and the injection volume 10 microL. Amino acid ingredient were derived by PITC, and then were detected with mobile phase of 0.1 mol x L(-1) sodium acetate buffer solution (pH 6.5) - acetonitrile, flow rate 1.0 mL x min(-1), column temperature 30 degrees C, and the injection volume 5 microL. Both of the absorption wavelengths were 254 nm. Pharmacopoeia Commission "Chinese chromatographic fingerprint evaluation system (version 2.0)" was adopted to analyse, fingerprints of Isatidis Radix micropower were established, at the same time 4 main ingredients were recognized by the SPSS cluster analysis.

Common mode of Fingerprint to water-soluble and amino acids ingredient of Isatidis Radix micropower was established, then adenosine, epigoitrin and 15 amino acids were identified as characteristic peaks. Cluster analysis showed that different kinds of the herbal Isatidis Radix micropower from different areas were different levels in the main ingredients.

Double fingerprints of Isatidis Radix micropower is established. Each peak is optimally separated in chromatogram, which provides a scientific basis for quality control of Isatidis Radix micropower.