Cation Profiles in Different Anatomical Parts of the Medicinal Plant Sambiloto (Andrographis paniculata) Determined by Ion Chromatography

Abstract

The cation composition of medicinal plants provides important information to characterize differences among their anatomical parts. This study determined six target cations, Li⁺, Na⁺, NH₄⁺, K⁺, Mg²⁺, and Ca²⁺, in the roots, stems, seeds, and leaves of Sambiloto (Andrographis paniculata) using ion chromatography (IC). Analysis was performed with a Metrohm Eco IC equipped with a Metrosep C4-150/4.0 column and a conductivity detector. The HNO₃ eluent concentration was optimized to 2.5 mM for separation at a flow rate of 0.8 mL/min and an injection volume of 10 µL. The method showed good analytical performance, with R² > 0.998, LODs of 0.024–0.284 mg/L, and RSDs of 1.89–3.04%. K⁺ was the predominant cation in all anatomical parts, ranging from 478.6 to 877.2 mg/kg. The highest Mg²⁺ concentration occurred in leaves (514.9 mg/kg), NH₄⁺ in seeds (147.9 mg/kg), and Ca²⁺ in stems (149.3 mg/kg) and leaves (138.5 mg/kg). Na⁺ was detected at moderate levels, while Li⁺ was not detected. Total cation contents were highest in leaves (1,554.5 mg/kg), followed by stems (1,196.6 mg/kg), seeds (1,089.3 mg/kg), and roots (730.1 mg/kg). These results demonstrate the effectiveness of IC for characterizing cation profiles across Sambiloto anatomical parts.