Determination of trace amounts of molybdate in soil by ion chromatography
Trace amounts of molybdate (MoO2–4) in soil were determined by single-column ion chromatography (SCIC). The method is based on the chromatographic separation of MoO2–4 from other inherent ions (Cl–, NO–3, PO3–4 and SO2–4) and was characterised in terms of time of analysis, detection limits and column efficiency. Separation of the anions was compared with the use of resin-based and polymethacrylate (PMA) gel analytical columns with 5 mMp-hydroxybenzoic acid (pH 8.25) as the mobile phase. The analytes were quantified by conductimetry with a detection limit of 45 µg l–1 of MoO2–4(signal to noise ratio = 3). The SCIC method for the determination of MoO2–4 with the PMA column gave good separation and the results were comparable to those obtained with inductively coupled plasma optical emission spectrometry.