## 3 Results and Discussion
### System Suitability and Method Validation of the Developed HPLC Analytical Method  
For efficient simultaneous analysis of markers in the DHGST sample, the suitability of the HPLC instrument was confirmed with respect to \(k^{\prime}\)(1.15-18.38), \(\alpha\) (1.01-1.75), \(N\) (16865-2158966), \(R\)s (1.27-18.17), and \(T\)/ (0.92-1.20) (Table S3). The regression equations for all the calibration curves showed excellent linearity, with a coefficient of determination (\(r^{2}\)) of 0.9999 to 1.0000 over the tested concentration range. The LOD and LOQ were calculated to be 0.004-0.061 ug/mL and 0.012-0.184 ug/mL, respectively (Table 1). Recovery was tested by adding three levels (low, medium, and high) of each standard solution to the DHGST sample, with results in the range of 95.47-102.81% (Table 2). The repeatability of the assay with respect to retention time and peak area was measured using a DHGST sample, and the RSD (%) was found to be \(\leq\)0.44% and \(\leq\)1.78%, respectively (Tables S4 and S5). Good RSD (%) values for intraday and interday precisions of \(\leq\)0.79% and \(\leq\)1.42%, respectively, were also recorded (Table 3). Having validated the method as described, it was concluded that the current HPLC simultaneous analysis method is suitable for the quality assessment of DHGST samples. Figure 1: Representative HPLC chromatograms of (**A**) standard solution and (**B**) 70% methanol extract of DHGST sample. Peaks correspond to gallic acid (**1**), 5-hydroxymethylfurfurfural (**2**), geniposidic acid (**3**), loganic acid (**4**), chlorogenic acid (**5**), gentiopicroside (**6**), pinoresinol diglucoside (**7**), albiforin (**8**), _prim-O_-glucosylclimifugin (**9**), paeoniflorin (**10**), liquiritin apioside (**11**), liquiritin (**12**), ferulic acid (**13**), nodakenin (**14**), 5-O-methylvisammioside (**15**), benzoic acid (**16**), coumarin (**17**), cinnamic acid (**18**), cinnamaldehyde (**19**), glycyrrhizin (**20**), methyleugenol (**21**), safrole (**22**), decursin (**23**), and decursinol angelate (**24**). \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Analyte**} & \multirow{2}{*}{**Quantification** **Wavelength** **(nm)**} & \multirow{2}{*}{**Linear Range** **(\(\mathbf{\mu g/mL}\))**} & \multirow{2}{*}{**Regression Equation a \(\mathbf{\boldsymbol{y}}=\boldsymbol{ax+b}\)**} & \multirow{2}{*}{**\(\boldsymbol{r^{2}}\)**} & \multirow{2}{*}{**LOD b (\(\mathbf{\mu g/mL}\))**} & \multirow{2}{*}{**LOQ c (\(\mathbf{\mu g/mL}\))**} \\  & & & & & & \\ \hline  
\hline \hline \end{tabular}  
* \(y\) and \(x\) indicate the peak area and concentration of each analyte, respectively; LOD b = \(3.3\times\sigma/S\) and LOQ c = \(10\times\sigma/S\) (where \(\sigma\) and \(S\) are the standard deviation of the \(y\)-intercept and the slope of the calibration curve, respectively).  
\end{table} 
Table 1: Linear range, regression equation, coefficient of determination (\(\boldsymbol{r^{2}}\)), limit of detection (LOD), and limit of quantification (LOQ) of 24 marker analytes for quantification by HPLC (\(n=3\)). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multicolumn{1}{c}{**Analyte**} & **Spiked Conc. (\(\mathbf{\mu g/mL}\))** & **Measured Conc. (\(\mathbf{\mu g/mL}\))** & **Recovery (\%) a \(\mathbf{\boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol{ \boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol{\boldsymbol,}}}}} }\boldsymbol{ }}}}}}}}}}}\)** & **SD** & **RSD (\%) b \\ \hline  & 2.00 & 2.00 & 100.04 & 0.77 & 0.77 \\
**1** & 4.00 & 4.08 & 101.92 & 0.98 & 0.96 \\  & 8.00 & 7.94 & 99.19 & 1.12 & 1.13 \\  & 2.00 & 1.97 & 98.46