RESUMO
ObjectiveTo investigate the influence of concentration ratio（CR） between the internal reference and target components on the quantitative accuracy of quantitative analysis of multi-components by single marker（QAMS） by taking ginsenosides as an example. MethodUltra performance liquid chromatography（UPLC） was employed， the contents of nine components in Ginseng Radix et Rhizoma（ginsenosides Rg1， Re， Rf， Rh1， Rb1， Rc， Rb2， Rb3， Rd） were determined by external standard method（ES）. Using ginsenoside Rg1 as the internal reference， the contents of the remaining 8 ginsenosides were determined by QAMS， and the quantitative results were compared with those of ES to evaluate the quantitative accuracy of the established QAMS. According to the contents of these 9 ginsenosides， the simulated sample solutions with different CRs of ginsenoside Rg1 to ginsenosides Rf， Rb2， Rd were prepared with the reference substance（CR=100∶1， 10∶1， 5∶1， 2∶1， 1∶1， 0.5∶1， 0.25∶1）， in order to validate the effect of the CRs between the internal reference and other components on the quantitative accuracy of the QAMS. ResultThe results of ginsenosides Re， Rf， Rb1， Rc， Rb2 calculated by the two methods were the same with the relative standard deviation（RSD）<3%， however， the results of ginsenosides Rh1， Rb3 and Rd calculated by the two methods were different with RSDs of 7.06%-9.61%. According to the result of the simulated sample solution， the difference between the calculated results of ES and QAMS was large when the CR between the internal reference（ginsenoside Rg1） and other components was 5 or 10 or even higher. ConclusionThe quantitative error of QAMS will increase when the CR between the quantitative component and the internal reference is too large， so it is suggested that when establishing the QAMS， the components with close concentration to the internal reference should be selected for quantification.
RESUMO
To establish the HPLC fingerprint and multi-component determination method of fried Glycyrrhizae Radix et Rhizoma pieces. HPLC analysis was performed on Thermo Acclaim ~(TM)120 C_(18) column(4.6 mm×250 mm, 5 μm). Acetonitrile-0.1% phosphoric acid aqueous solution was taken as the mobile phase for gradient elution. The flow rate was 1 mL·min~(-1),the column temperature was maintained at 30 ℃, and the detection wavelength was 237 nm and 360 nm. The similarity of 15 batches of fried Glycyrrhizae Radix et Rhizoma pieces was higher than 0.849, and 17 common peaks were identified. Liquiritin, isoliquiritin apioside, isoliquiritin, liquiritigenin, isoliquiritigenin and glycyrrhizic acid were identified; among them, the mass fractions of Liquiritin, isoliquiritin apioside, isoliquiritin, liquiritigenin, glycyrrhizic acid were were 0.519%-3.058%, 0.227%-0.389%, 0.070%-0.439%, 0.038%-0.173%, 1.381%-4.252%, respectively. According to the cluster analysis, the 15 batches of decoction pieces were classified into three categories; principal component analysis screened out four principal components, with the cumulative variance contribution rate of 86.630%, indicating that the principal components contained most information of original data. Partial least squares discriminant ana-lysis marked 6 differential components in the decoction pieces. The established fingerprint and multicomponent determination are stable and reliable, and can provide a reference for the quality control of Radix Glycyrrhizae Radix et Rhizomae and fried Glycyrrhizae Radix et Rhizoma pieces.