Separation and determination of four active anthraquinones in Chinese herbal preparations by flow injection-capillary electrophoresis

Abstract

A simple, rapid, and accurate method for the separation and determination of physcion, chrysophanol, aloe-emodin, and emodin in Rhubarb, Juemingzi, and Chinese herbal preparations was developed by combination of flow injection-capillary zone electrophoresis for the first time. The analysis was carried out using an unmodified fused-silica capillary (75 mm x 50 microm ID x 375 microm OD, effective separation length of 48 mm) and direct ultraviolet detection at 254 nm. By a series of optimization, the sample solvent consisted of NaOH (100 mmol/L) and ACN (1:1 v/v), and a running buffer composed of 15 mmol/L sodium borate - 12.5 mmol/L sodium dihydrogen phosphate - 42% v/v ACN (pH 10.1) was applied for the separation of the four anthraquinones. The separation was rapid and highly reproducible, with complete resolution of all four compounds within 6 min. The sample throughput rate could reach up to 12 per h. The repeatability (defined as relative standard deviation) was 4.45, 4.44, 4.34, 0.61% with peak height evaluation and 1.62, 0.89, 2.49, 2.19% with peak area evaluation for physcion, chrysophanol, aloe-emodin, and emodin, respectively.

Analysis of phenolic compounds in rhubarbs using liquid chromatography coupled with electrospray ionization mass spectrometry

“…Therefore, a simple, rapid, and accurate method for the analysis of bioactive compounds in rhubarb is necessary for the quality control of crude rhubarb drugs and their pharmaceutical preparations. Qualitative and quantitative analyses of rhubarbs have been extensively pursued [11][12][13][14]. However, most of these investigations focus on the determination of anthraquinones by TLC, HPLC, and HPCE.…”

Combination of flow injection with electrophoresis using capillaries and chips

“…The device was produced using commercial capillary and components readily available in analytical laboratory. Later, the performance of the combined system was further demonstrated by the separation of honokiol and magnolol in herbal medicines [18], the separation of four active anthraquinones in Chinese herbal preparations [19] and the determination of tetrandrine and fangchinoline in herbal medicine [20]. Compared to conventional sample introduction for CE by electrokinetic or gravitational means, the combined system was characterized by easy automation with significantly enhanced sampling frequency and outstanding reproducibility in migration time, peak area, and peak height.…”

Novel Gas-assisted Three-liquid-phase Extraction System for Simultaneous Separation and Concentration of Anthraquinones in Herbal Extract

“…At gas flow rate higher than 30 ml·min − 1 , separation equilibrium can be achieved in 25 min. Because of their physiochemical property difference [32,33], emodin is more hydrophobic than rhein and is more likely to be absorbed on the bubble surface. Therefore, emodin is removed faster than rhein, and the remanent mass fraction in the aqueous phase is less.…”