This application note describes a method for quantifying three alkaloids in the stem of various mahonia species: berberine, palmatine, and jatrorrhizine. The method uses capillary electrophoresis (CE), which is particularly suited to the analysis of plant extracts because of its ability to deal with complex or “dirty” sample matrices.
This document details a method for quantifying three specific alkaloids—berberine, palmatine, and jatrorrhizine—in Mahonia stem extracts. The authors highlight that capillary electrophoresis (CE) is particularly suitable for this analysis due to its ability to handle complex or 'dirty' sample matrices without the column packing issues associated with HPLC.
The note provides specific experimental conditions, including sample preparation using ultrasonication and methanol extraction, and CE parameters such as capillary dimensions, buffer composition (50 mM phosphate/borate with 50% methanol), voltage (30 kV), and detection wavelengths (200 nm and 265 nm). Results indicate linear detection ranges for all three alkaloids with high reproducibility.
| Injection time | 10 sec |
|---|---|
| Capillary length | 48.5 cm total, 40 cm effective |
| Capillary inner diameter | 50 pm |
| Buffer composition | 50 mM phosphate, 50 mM borate containing 50 % methanol |
| Applied voltage | 30 kV |
| Operating temperature | 20°C |
Berberine is linear from 3.4-109 mg/mL, palmatine from 1.4-44 mg/mL, and jatrorrhizine from 1.1-37 mg/nL.
The recommended buffer is 50 mM phosphate and 50 mM borate containing 50% methanol.
The analysis is performed at an applied voltage of 30 kV.