Development of HPLC method for the determination of gastrodin and para-hydroxybenzyl alcohol in tall gastrodia tuber on the polyglycol-C-8 column

Compared with the C-8 and C-18 reversed phases the polyglycol-C-8 bonded ph ase synthesized in this laboratory exhibits strong retention and different selectivity to hydrophilic solutes. Their characteristic advantages were us ed to develop a HPLC method for the analysis of the active components, gast rodin and p-hydroxybenzyl alcohol, in tall gastrodia tuber. The chromatogra phic conditions were optimized by means of computer-assisted method develop ment technique. DryLab software was used to model the retention behavior of the compounds as a function of gradient conditions, based on the data from two scouting gradient runs. Under the optimized conditions: column, polygl ycol-C-8, 5 mum, 25 x 0.46-cm; solvent A, 25 mM phosphate buffer, pH 2.7/ m ethanol, 95/ 5 (V/ V); solvent B, methanol; gradient, 0/ 0/ 70% B at 0/ 10/ 40 min; flow rate, 0.5 mL/ min; temperature, ambient, the quality of tall gastrodia tuber from different sources were evaluated. Meanwhile, the three methods for sample preparation were discussed. When the sample is prepared by refluxing in mater, the analytical results reflect the sum of gastrodin and p-hydroxybenzyl alcohol existing in the free form and produced from th e hydrolysis of gastrodioside.