Simultaneous Determination of Ag, W and Mo in Geochemical Exploration Samples by ICP-MS Using P₅₀₇ Loaded Foam for Separation

When determining Ag in geochemical exploration samples by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), the molecular ions ⁹¹Zr¹⁶O and ⁹³Nb¹⁶O can seriously interfere with the isotopes ¹⁰⁷Ag and ¹⁰⁹Ag and need to be separated out to obtain accurate results. The application of P₅₀₇ levextrel resin to separate the interfering elements of Zr and Nb was recently successfully conducted to in the determination of Ag in exploration samples. In this study, this method was improved by using P₅₀₇ loaded foam to absorb the interference elements with vibration and in measuring Ag, W and Mo by ICP-MS. The sample was digested by HF, HNO₃, HClO₄ and reverse aqua regia in an open system. The results of reference materials agree well with the certified values. The detection limits of Ag, W and Mo are 0.0045 μg/g, 0.023 μg/g, 0.060 μg/g, respectively, which are lower than the detection limits of multi-target geochemical exploration (1: 250000). The proposed method is more simple and rapid than the method of P₅₀₇ levextrel resin and can be used for routine determination of Ag, W, Mo and trace elements in large amounts of geochemical exploration samples.