Quantification of Ginsenoside Content in Ginseng

The gross ginsenosides content was determined by using the reference method of the State Standard of the People's Republic of China (GB/T 19506-2009): GF powder (passed through a 60-mesh sieve) was accurately weighed (about 1.0 g) then packaged in a neutral filter paper. The powder was extracted with ether using a Soxhlet extractor for 1 h. The sample package was then dried to evaporate the ether solvent. Methanol was added to the extractor to soak overnight. The next day, the appropriate amount of methanol was added to repeat the extraction for 6 times. The methanol extracts were combined and recovered, steaming a small amount of methanol extracts in the water bath and then dissolving them in water. 30 mL water extract was extracted for 4 times with 30 mL of water-saturated n-butanol. The upper liquid was steamed, then dissolved in methanol and made up to 10 mL. Finally, the end product was used as the ginsenosides sample solutions for further analysis.
The total ginsenoside content was determined using the reference method of the product of geographical indication-Jilin Changbaishan ginseng (GB/T 19506-2009), Ginsenoside Re (National Institutes for Food and Drug Control, Beijing, China)was used as the standard to calculate the content of the gross ginsenoside. In order to prepare the ginsenoside Re standard solution, 10 mg ginsenoside Re was put into a 10 mL volumetric flask, dilute to scale with methanol as solvent and mixed. 10 μL, 20 μL, 30 μL, 40 μL, 60 μL, 80 μL, and 100 μL of the standard solution and 30 μL sample solution were transferred to 10 mL tubes and dried (60°C water bath). Then, 0.5 ml 8% vanillin-ethanol and 5 ml 72% concentrated sulfuric acid were added to the prepared tubes. After fully shaking and mixing, the solution was heated in a 60°C water bath for 10 min and then cooled down in an ice-water bath for 10 min immediately. The mixed reagent without ginsenoside was used as a reference. Finally, both were determined at 544 nm using an enzyme calibration (Infinite M200 PRO, Tecan, Switzerland). To reduce the error in determining the gross ginsenosides content, three parallel extracts were obtained from the same origin of GF raw materials. The changes in gross ginsenosides content in GFs of various ages were then compared. The following equation was used to calculate the gross ginsenoside content:
Equation (1) of Cui et al. [22 (link)] was used to calculate the gross ginsenosides content: $\begin{array}{c}\mathrm{X}\left(\%\right)={\mathrm{m}}_1\ast \frac{\left({\mathrm{A}}_2/{\mathrm{A}}_1\right)}{{\mathrm{m}}_2}\ast 100\%\text{,}\end{array}$ where X is the gross ginsenosides content; m₁ represents the weight of ginsenoside Re, m₂ is the weight of GF powder, and A₁ and A₂ are the absorbances of the ginsenoside Re standard solution and sample solution, respectively.