Simultaneous analysis of seven alkaloids in Coptis-Evodia herb couple and Zuojin pill by UPLC with accelerated solvent extraction

A rapid, sensitive, and accurate ultra-performance liquid chromatography-UV detection method was developed and validated for simultaneous determination of seven active alkaloids, berberine, palmatine, coptisine, jatrorrhizine, epiberberine, evodiamine, and rutaecarpine, in the Coptis-Evodia herb couple and the Zuojin pill preparation. The original validated method had a total time of about 11 min, which was reduced to 4.7 min by further optimization of gradient elution conditions with eluent A comprising water/methanol/formic acid (v/v/v, 90:10:0.1) and eluent B ACN. An accelerated solvent extraction method was used for the rapid extraction of herb products and pill preparations. Linear behavior over the investigated concentration ranges was observed, with values of r(2) greater than 0.9987 for all analytes. Experiment results were satisfactory for both intra-day and inter-day precision, and method accuracy. Method recovery ranged from 95.7 to 103.5% based on pure reference standards. The validated method was successfully applied to determine amounts of bioactive alkaloid compounds in five samples, in the Coptis-Evodia herb couple, and the commercial Zuojin pill products. The developed method achieved baseline resolution for all seven main basic compounds and is suitable for use as a routine procedure for the rapid identification and quantification of basic compounds in the Coptis-Evodia herb couple and related products.