A fast and convenient analysis method for the determination of cations in pomegranate juices by capillary electrophoresis with contactless conductivity detection

Health beneficial effect of pomegranate is mainly due to its confirmed high antioxidant capacity and polyphenolic content. In recent years, experimental and clinical studies have shown that pomegranate intake lowers blood pressure. Potassium and other minerals such as calcium and magnesium may be responsible for this property. In this study, a rapid, economic, reliable, and applicable capillary electrophoresis method was proposed with contactless conductivity detection for the quantitative determination of six cations in different pomegranate juices. The correlation between these cation contents of eight different pomegranate juices was evaluated by using one-way ANOVA and Duncan’s multiple-range test. The optimum buffer composition was selected as 20 mM 3-(N-morpholino) propanesulfonic acid (MOPS) and 2.5 mM 18-crown-6 at pH 7.5. The proposed method was validated for NH ⁺ ₄ , K ⁺ , Ca ²⁺ , Mg ²⁺ , Na ⁺ , Li ⁺ ions. These cations were quantified in different freshly squeezed and commercial pomegranate juices with recovery values between 94.1% and 103.1%. Potassium was found as the predominant mineral, reaching up to 2380 mg/L.