肥料中水溶性钾含量测定的四苯硼酸钾重量法改进及国际标准制定

Improvement on Determination of Water-soluble Potassium Content in Fertilizers by Potassium Tetraphenylborate Gravimetric Method and Development of Related International Standard

对肥料和土壤调理剂中水溶性钾含量测定应用最广泛的分析方法——四苯硼酸钾重量法进行系统研究与改进,取消了现有方法中添加甲醛以掩蔽NH+4的步骤。通过对标准物质和一系列有代表性的肥料样品的对比实验分析,验证了新方法具有更高的准确性和与原方法相当的精密度。经国际标准化组织肥料与土壤调理剂专业委员会推荐,由上海化工研究院牵头组织国内外14家分析实验室进行了实验室间比对,统计结果表明,新方法的适用性好且精密度高,因此将推荐其作为新国际标准分析方法。

The most wildly used analytical method for determination of water-soluble potassium content in fertilizers and soil conditioners, namely the potassium tetraphenylborate gravimetric method, is systematically studied and improved, and the procedure of masking ammonium by adding formaldehyde is abolished. Comparative experiments on both reference materials and a series of fertilizer samples show that the newly-developed method is more accurate than the former method, and of compatible precision. Recommended by the ISO Technical Committee 134 （Fertilizers and Soil Conditioners）, an international ring test with 14 participating labs around the world is conducted by the Shanghai Research Institute of Chemical Industry. Statistical analysis reveals that the new method is both universal and precise, thus it will be approved as the next-generation analytical method for the new ISO standard.