Analysis of alkaloids in <i>Ipecacuanhae radix</i> and preparations by capillary zone electrophoresis

Abstract

Abstract A capillary zone electrophoresis method for quantitation of the alkaloids emetine and cephaeline in Ipecacuanhae radix fluid extract and Ipecac syrup using papaverine as internal standard is described. Baseline separation was achieved within 10 min using a fused silica capillary and a running electrolyte consisting of citric acid (50 mM), disodium hydrogenphosphate (100 mM), and 2.5% methanol (pH 4.4). Regression equations revealed a linear response from 0.05 to 1.9 mg/mL for cephaeline and emetine (correlation coefficients 0.9991–0.9993). The lowest quantitation limits were determined as 0.03 mg/mL for both alkaloids, and the limit of detection was 0.012 mg/mL. The day‐to‐day variations of retention times were &lt; 1.3% for both compounds. Whereas no sample pre‐treatment was necessary for analysis of the fluid extract, SPE had to be applied before CE analysis of the syrup. The recovery rate for emetine in this case was &gt; 99.8%.