ABSTRACT
This study aimed to establish a method for positioning six chromatographic peaks occurred in HPLC profile of Gastrodiae Rhizoma. The "liner calibration with two reference substances" (LCTRS) method was used to calculate the retention time so as to assist in positioning of chromatographic peaks in terms of the prediction accuracy of retention time and the coincidence rate of chromatographic column. A total of 24 C18 chromatographic columns from different brands and types available were used to determine the retention times of six components in Gastrodiae Rhizoma, then the average retention time of each component was obtained as standard retention time (SRT). Parishin E (peak 3) and Parishin A (peak 6) were simultaneously taken as reference substance to forecast the retention time of the other four components by using the LCTRS method. Four different C18 columns were employed to verify the method. Meanwhile, for the purpose of comparison, the relative retention time (RRT) method was applied to forecast the retention time, by using Parishin E as the single reference substance. The comparison between LCTRS and RRT methods indicated that the former was more accurate in predicting the retention time and more applicable in utilization of chromatographic columns. This study demonstrated that the LCTRS method shows the superior performance in positioning of chromatographic peak, and therefore has a good prospect of application.