DEVELOPMENT OF HPLC METHOD FOR THE DETERMINATION OF GASTRODIN AND PARA-HYDROXYBENZYL ALCOHOL IN TALL GASTRODIA TUBER ON THE POLYGLYCOL-C8 COLUMN

Compared with the C8 and C18 reversed phases the polyglycol-C8 bonded phase synthesized in this laboratory exhibits strong retention and different selectivity to hydrophilic solutes. Their characteristic advantages were used to develop a HPLC method for the analysis of the active components, gastrodin and p-hydroxybenzyl alcohol, in tall gastrodia tuber. The chromatographic conditions were optimized by means of computer-assisted method development 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, polyglycol-C8, 5 µm, 25 × 0.46-cm; solvent A, 25 mM phosphate buffer, pH 2.7/ methanol, 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 water, the analytical results reflect the sum of gastrodin and p-hydroxybenzyl alcohol existing in the free form and produced from the hydrolysis of gastrodioside.