Sensitive Determination of Saponins in Radix et Rhizoma Notoginseng by Charged Aerosol Detector Coupled with HPLC

Abstract

With continuous development in analytical instruments over recent years, high performance liquid chromatography (HPLC) with various detectors has become very important tools for routine analysis and quality control of TCMs and botanical medicines. As a new ''mass'' detector, charged aerosol detector (CAD) provides an alternative detection method, which ultraviolet (UV) is unable to achieve for components owning almost no chromophore in its chemical structures with the lower sensitivity. With the purpose of evaluating the applicability of CAD for the analysis of TCMs, an HPLC-CAD method for simultaneous determination of saponins in Radix et Rhizoma Notoginseng (''Sanqi'' in chinese) was established in this contribution, which was successfully applied for quantitation of seven saponins, notoginsenoside R 1 , ginsenosides Rg 1 , Re, Rb 1 , Rg 2 , Rh 1 , and Rd, in thirty batches of Sanqi samples. Meanwhile, the LODs and LOQs of UV, ELSD and CAD were compared and the results showed that the CAD method exhibited a lower LOD (0.01 $ 0.15 mg) and LOQ (0.04 $ 0.41 mg) than UV and ELSD. Furthermore, the CAD exhibited a steadier baseline in gradient elution compared with UV at 203 nm. Also, the HPLC-CAD method presents many apparent advantages of high sensitivity, steady baseline in gradient elution, easy operating, and it was expected to be a sensitive and universal method for analysis of TCMs containing weak UV absorption compounds. It was demonstrated that the content of seven saponins in Radix et Rhizoma Notoginseng did not significantly correlate with the original work nor with the conventional quality standard.

Recent Methodology in Ginseng Analysis

“…Using an HPLC-CAD system, Bai et al . [42] and Wang et al . [43] simultaneously quantified ginsenosides in P. ginseng and P. notoginseng .…”

Optimization of pressurized liquid extraction for spicatoside A in Liriope platyphylla

“…been considered as important chemical markers to reflect the characteristics of the medicinal plants. However, it is difficult to determine saponins by a UV detector, for they mostly subject to no chromophores in their structures and the UV absorption is weak or only has end absorption [13]. To overcome these problems, several trails were performed to apply evaporative light scattering detection (ELSD) and CAD for detection of saponins.…”

“…It has been reported that high performance liquid chromatography coupled with charged aerosol detector (HPLC-CAD) method owned the superiority of good reproducibility and excellent sensitivity for the determination of weak chromophore compounds such as saponins [13]. Thus a method for the quantitative determination of spicatoside A was developed using HPLC-CAD.…”

Isolation and analysis of ginseng: advances and challenges

“…Bai et al 183 established an HPLC-CAD method for quantitative analysis of notoginsenoside R1, ginsenosides Rg1, Re, Rb1, Rg2, Rh1, and Rd in 30 batches of P. notoginseng samples. The sensitivity of CAD was higher than that of ELSD or UV.…”