A convenient approach for the quality assessment of Vietnamese ginseng ( Panax vietnamensis ) in cultivation regions

The limited resolving capability of reversed‐phase stationary phase prevents effective separation of ginsenoside Re (G‐Re) from ginsenoside Rg1 (G‐Rg1) or majonoside R2 (MR2). Although amino stationary phase can separate these compounds, their application in ginseng quality assessment is constrained by Schiff base reactions with reducing sugars. To enable on‐site quality evaluation of Vietnamese ginseng in cultivation regions around Ngoc Linh Mountain, this study employed primary and secondary amine material as a solid‐phase extraction adsorbent to remove reducing sugars from sample solutions, thereby protecting the amino stationary phase. Consequently, the levels of G‐Rg1, MR2, G‐Rd, and G‐Re were quantified by HPLC coupled with refractive index detection (HPLC‐RID), using a SiliaChrom Plus Amine column (4.6 × 250 mm, 5 µm, 100 Å) under isocratic elution with acetonitrile, water, and butanol (120:25:15,v/v). The method exhibited a linear range of 250–4000 µg/mL with strong linearity ( R 2 > 0.995), and detection limits for the four ginsenosides ranged from 128.12 to 255.45 µg/mL. Reproducibility testing yielded %RSD values below 3%, and recovery results between 98.9% and 101.0% confirmed accurate quantification. These findings demonstrate that the developed HPLC‐RID method reliably determines key ginsenosides in Vietnamese ginseng for on‐site quality assessment.