Non-aqueous capillary electrophoresis for separation and simultaneous determination of fraxin, esculin and esculetin inCortex fraxini and its medicinal preparations

Abstract

A non-aqueous capillary electrophoresis method has been developed for the separation and simultaneous determination of fraxin, esculin and esculetin in Cortex fraxini and its preparation for the first time. Optimum separation of the analytes was obtained on a 47 cm x 75 microm i.d. fused-silica capillary using a non-aqueous buffer system of 60 mM sodium cholate, 20 mM ammonium acetate, 20% acetonitrile and 3% acetic acid at 20 kV and 292 K, respectively. The relative standard deviations (RSDs) of the migration times and the peak heights of the three analytes were in the range of 0.23-0.28 and 2.12-2.60%, respectively. Detection limits of fraxin, esculin and esculetin were 0.1557, 0.4073 and 0.5382 microg/mL, respectively. In the tested concentration range, good linear relationships (correlation coefficients 0.9995 for fraxin, 0.9999 for esculin and 0.9992 for esculetin) between peak heights and concentrations of the analytes were observed. This method has been successfully applied to simultaneous determination of the three bioactive components with the recoveries from 90.2 to 109.2% in the five samples.

Untargeted metabolite analysis of healthy and Huanglongbing‐infected orange leaves by CE‐DAD

“…In addition, NACE is particularly suitable for analytes that are not readily soluble in aqueous BGE [40]. Concentrations of ACN ranging from 5 to 50% in methanol were tested along with ethanol amide to increase the pH of the organic solution.…”

Quality control of herbal medicines by capillary electrophoresis: Potential, requirements and applications

“…Separation was achieved in a 10 mM borax buffer, containing SDS and acetonitrile as additives, for quantification an internal standard (coumarin) was used. Three coumarins (fraxin, esculin and esculetin) were assayed in medicinal preparations of Cortex Fraxini, a popular TCM remedy for the treatment of enteritis and nephritis [79]. The BGE was a 20 mM solution of ammonium acetate, containing 3% acetic acid and 20% ACN; micelles were formed by adding sodium cholate.…”

Carbon nanotube/poly(ethylene‐co‐vinyl acetate) composite electrode for capillary electrophoretic determination of esculin and esculetin in Cortex Fraxini

“…Because both esculin and esculetin were found presented in all the three samples, they can be defined as characteristic markers in the fingerprint of Cortex Fraxini under the selected conditions. The determined contents of esculin and esculetin in Cortex Fraxini are well in agreement with a previous report (6.779À27.89 mg/g for esculin and 1.044À1.757 mg/g for esculetin, respectively) [34]. To prevent the degradation of the analytes, the stock solution and the extracts of the plant samples were diluted using the running buffer just before CE analysis.…”

“…Ultraviolet (UV) spectrometry [31] and LC [32,33] have been employed in the simultaneous determination of esculin, esculetin, and other coexistent constituents in Cortex Fraxini. In addition, CE [34,35] has also been employed for the quantitative determination of esculin and esculetin in Cortex Fraxini using UV detectors. Because the absorbance path length of the capillary (the typical inner diameter, 25-100 mm) is very short, the low sensitivity of the UV detector used results in poor detection limit.…”