标准摘要
[中文适用范围]： 适用于F含量等于或大于0.5mg/kg的产品。 指定在磷酸介质中通过蒸汽蒸馏从测试部分中分离元素。 在 pH 值为 4.6 的缓冲介质中，与组合试剂茜素络合物/硝酸镧形成蓝色络合物。 添加丙酮以增加复合物的稳定性和灵敏度。 在约 600 nm 波长下对复合物进行光度测量。 [外文原描述]： Applicable to products the F content of which is equal to or more than 0.5 mg/kg. Specifies the separation of the element from a test portion by steam distillation in a phosphoric acid medium. Formation of a blue-coloured complex with a combined reagent alizarin complexone/lanthanum nitrate in a buffered medium at the pH of 4.6. Addition of acetone to increase the stability of the complex and the sensitivity. Photometric measurement of the complex at a wavelength of about 600 nm.
英文名称Phosphoric acid and sodium phosphates for industrial use (including foodstuffs) — Determination of fluorine content — Alizarin complexone and lanthanum nitrate photometric method