Key Laboratory of Biogeology and Environmental Geology of Ministry of Education, Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074, PR China.
Sci Total Environ. 2011 Jul 1;409(15):2981-6. doi: 10.1016/j.scitotenv.2011.04.011.
Silver is subject to significant spectral interferences caused by high concentrations of Zr, Nb, Mo and Y in inductively coupled plasma mass spectrometry (ICP-MS) analysis for soil or sediment samples. In this study, the Zr, Nb, and Mo based oxide and/or hydroxide polyatomic interferences were successfully eliminated by ion-molecule reactions in a dynamic reaction cell (DRC). These potentially interfering ions ⁹³Nb¹⁶O+, ⁹²Zr¹⁶OH+ and ⁹²Mo¹⁶OH+ on ¹⁰⁹Ag+ were rapidly oxidized to higher oxides ⁹³NbO₂+, ⁹²ZrO₂H+/⁹²ZrO₂H+ and ⁹²MoO₂H+ by O₂ as the reaction gas in DRC. However, interfering ions ⁸⁹Y¹⁸O+ and ⁹¹Zr¹⁶O+ on ¹⁰⁷Ag cannot be removed by this method, because the reaction rates of ZrO+ and YO+ to ZrO₂+/ZrO₃+ and YO₂+/YO₃+ were too low. Under the optimized O₂ flow rate (2.4 mL min⁻¹) and DRC rejection parameter q (Rpq, 0.75), the background signal was reduced by up to 100-fold at m/z 109 and the limit of quantitation (LOQ, 10σ) for ¹⁰⁹Ag was 0.5 ng g⁻¹. The proposed method was used to determine the concentration of Ag in twenty-eight soil standard reference materials (SRMs). The accuracy of the results suggests that the method has great potential for the direct determination of trace or ultra-trace levels of Ag in various environmental samples.
银在电感耦合等离子体质谱（ICP-MS）分析土壤或沉积物样品时，受到 Zr、Nb、Mo 和 Y 高浓度引起的显著光谱干扰。在这项研究中，通过在动态反应池（DRC）中离子-分子反应成功消除了基于 Zr、Nb 和 Mo 的氧化物和/或氢氧化物多原子干扰。这些潜在的干扰离子 ⁹³Nb¹⁶O+、⁹²Zr¹⁶OH+和 ⁹²Mo¹⁶OH+在 DRC 中迅速被 O₂作为反应气体氧化为更高的氧化物 ⁹³NbO₂+、⁹²ZrO₂H+/⁹²ZrO₂H+和 ⁹²MoO₂H+。然而，这种方法不能去除干扰离子 ⁸⁹Y¹⁸O+和 ⁹¹Zr¹⁶O+，因为 ZrO+和 YO+与 ZrO₂+/ZrO₃+和 YO₂+/YO₃+的反应速率太低。在优化的 O₂流速（2.4 mL min⁻¹）和 DRC 排斥参数 q（Rpq，0.75）下，在 m/z 109 处的背景信号降低了 100 倍，109Ag 的定量限（LOQ，10σ）为 0.5 ng g⁻¹。该方法用于测定 28 个土壤标准参考物质（SRM）中 Ag 的浓度。结果的准确性表明，该方法在直接测定各种环境样品中痕量或超痕量 Ag 方面具有很大的潜力。
