Simultaneous determination of silicic acid, Ca, Mg and Al in mineral water and composite tablets by Ion chromatography

• Published in: Chromatographia Vol. 53; no. 1-2; pp. 81 - 84
• Main Authors: Xu, Q, Xu, C, Zhang, W, Wang, Y. P, Jin, L. T, Haraguchi, H, Itoh, A, Tanaka, K
• Format: Journal Article
• Language: English
• Published: Oxford Vieweg Verlag 2001; Springer
• Subjects: aluminum; Analysis; Analytical chemistry; anions; Biological and medical sciences; calcium; cations; Chemistry; chlorides; Chromatographic methods and physical methods associated with chromatography; detection limit; EDTA; EDTA (chelating agent); Exact sciences and technology; General pharmacology; ion exchange chromatography; ions; magnesium; Medical sciences; mineral water; nitrates; Other chromatographic methods; Pharmacology. Drug treatments; silicic acid; sodium; sodium hydroxide; Trace analysis; Complexation; Natural mineral water; Chemical analysis; Phase composition; Silicic acid; Inorganic ion; Nitrates; Calcium Ions; EDTA; Mobile phase; Electrochemical detector; Inorganic cation; Ion chromatography; Multicomponent analysis; Inorganic anion; Conductometry; Chlorides; Simultaneous measurement; Dosage form; Magnesium Ions; Tablet; Aluminium Ions; Quantitative analysis
• ISSN: 0009-5893; 1612-1112
• DOI: 10.1007/bf02492432

A simple, selective and sensitive ion-chromatography method was investigated for simultaneously determining silicic acid, Ca²⁺, Mg²⁺, Al³⁺ and anions (Cl⁻ and NO ₃ ⁻) in real samples. It involved a single-column ion-chromatograph with sodium hydroxide-methanol-water eluent and conductometric detection. Cations were converted to complex anions by adding EDTA to the sample solution. A set of well-defined peaks of silicic acid, Ca²⁺, Mg²⁺, Al³⁺, Cl⁻ and NO ₃ ⁻ were obtained. Detection limits using 3.3σ (σ=standard deviation of blank solution) were 1.25×10⁻⁶ M for H₃SiO ₄ ⁻ , 1.32×10⁻⁶ M for Ca²⁺, 1.28×10⁻⁶ M for Mg²⁺, 1.33×10⁻⁶ M for Al³⁺, 1.31×10⁻⁶ M for Cl⁻ and 1.24×10⁻⁶ M for NO ₃ ⁻ . The method was successfully applied to analysis of mineral water and composite tablets.