Abstract The use of tetrafluoroboric acid and sodium hydroxide were investigated for the total decomposition of plant tissues and fertilizers for Si determination by microwave-induced plasma optical emission spectrometry (MIP OES). The accuracy was estimated by comparing the results of the proposed method with those of energy dispersive X-ray fluorescence (ED-XRF). The optimized HBF4 volume required to decompose 100 mg of sample was estimated to be 0.2 mL (48% w v−1). The Si recovery obtained was 99%, and the limit of detection was 0.03 g kg−1. Concerning the reactions and the possible products formed, after digestion 70% of the Si was found as fluorosilicic acid. Besides this, hydrofluoric acid was formed. High dilution factors, the addition of excess boric acid, or the use of a sample introduction system manufactured from inert components can be adopted to avoid damage to the MIP OES components and contamination of the analytical blank. The introduction of air in the N2 plasma was assessed to reduce the matrix effect noted due to high sodium concentration in the alkaline digestion, and improved accuracy was achieved. The Si recoveries obtained by applying this method varied from 100 to 102%, and the limit of detection was 0.4 g kg−1.

中文翻译：

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通过微波诱导等离子体发射光谱法测定硅：在样品制备过程中使用四氟硼酸和氢氧化钠的注意事项和策略

摘要 研究了四氟硼酸和氢氧化钠在植物组织和肥料的总分解中的应用，以通过微波诱导等离子体发射光谱法 (MIP OES) 测定硅。通过将所提出方法的结果与能量色散 X 射线荧光 (ED-XRF) 的结果进行比较来估计精度。分解 100 mg 样品所需的优化 HBF4 体积估计为 0.2 mL (48% wv-1)。获得的硅回收率为 99%，检测限为 0.03 g kg-1。关于反应和可能形成的产物，消化后发现 70% 的 Si 为氟硅酸。除此之外，还生成了氢氟酸。高稀释因子，添加过量硼酸，或使用由惰性组件制成的进样系统，以避免损坏 MIP OES 组件和污染分析空白。评估在 N2 等离子体中引入空气以减少由于碱性消化中钠浓度高而引起的基质效应，并提高了准确性。通过应用该方法获得的硅回收率从 100% 到 102% 不等，检测限为 0.4 g kg-1。