Fluosilicic acid is a by-product of the chemical phosphate industry, mainly during the manufacture of phosphoric acid and triple super phosphate (TSP). To ensure the accurate measurement of the H₂SiF₆ mass fraction in this by-product, method validation is required, which needs a certified reference material (CRM) with its traceability to the International System of Units (SI). This work describes the development of a certified reference material of fluosilicic acid, which is commercially unavailable. Details of all steps, such as sample preparation, homogeneity and stability studies, value assignment, establishment of metrological traceability, and uncertainty estimation of the certified reference material, are fully described. The H₂SiF₆ mass fraction in the CRM was quantified by two analytical methods, i.e., UV-VIS as a primary method of analysis and flame mode atomic absorption spectroscopy (AAS) as a second method. It is worth noting that the results obtained from each method were in good agreement. The CRM certified value and corresponding expanded uncertainty, obtained from the combined standard uncertainty multiplied by the coverage factor (k = 2), for a confidence interval of 95%, was (91.5 ± 11.7) g·kg⁻¹. The shelf life of the developed CRM is determined to be 1 year, provided that storage conditions are ensured. The developed CRM can be applied to validate analytical methods, improve the accuracy of measurement data as well as to establish the meteorological traceability of analytical results.

中文翻译：

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内部工业氟硅酸认证参考材料的开发：H2SiF6质量分数认证

氟硅酸是化学磷酸盐工业的副产品，主要在制造磷酸和三重超磷酸盐（TSP）的过程中。为了确保该副产物中H ₂ SiF ₆质量分数的准确测量，需要进行方法验证，该方法需要可追溯至国际单位制（SI）的认证参考材料（CRM）。这项工作描述了氟硅酸认证参考材料的开发，这是商业上无法获得的。完整描述了所有步骤的详细信息，例如样品制备，均质性和稳定性研究，值分配，计量溯源的建立以及认证参考物质的不确定性估计。H ₂ SiF ₆CRM中的质量分数通过两种分析方法进行定量，即UV-VIS作为主要分析方法，火焰模式原子吸收光谱法（AAS）作为第二种方法。值得注意的是，从每种方法获得的结果都吻合良好。在95％的置信区间内，从组合标准不确定度乘以覆盖因子（k = 2）获得的CRM认证值和相应的扩展不确定度为（91.5±11.7）g·kg ^-1。只要确保存储条件，开发的CRM的保质期确定为1年。开发的CRM可以用于验证分析方法，提高测量数据的准确性以及建立分析结果的气象可追溯性。