Development and optimization of a method for the analysis of Brazilein by HPLC with electrochemical detection

The aim of this study was to establish an easy and accurate method for the determination of Brazilein in plant samples due to its potential pharmacological activities. High-performance liquid chromatography (HPLC) with electrochemical detection (ED) was used for the assay of Brazilein in this study for the first time. Crucial influence parameters including concentration of dodecane-1-sulfonic acid sodium salt (DSASS), inorganic modifier, tetrabutyl-ammonium hydroxide solution (TBAOH), and applied potential of proposed method were investigated. The proposed method is simple, rapid (analysis time: ∼10 min), sensitive [(detection limit: 0.6 ng per injection (20 μl) at a signal-noise ratio 3:1)], highly selective and precise (intra- and inter-day precisions were within 5%, n = 7). The calibration graph of Brazilein was linear in the range 0.6-150 ng per injection 20 μl. Recovery of Brazilein was over 92% by standard addition method.