标准摘要
[中文适用范围]： 其原理在于通过用硫酸或高氯酸蒸馏从测试部分中分离氟。 以茜素磺酸钠和亚甲基蓝为指示剂，用硝酸钍溶液滴定。 或者，可以单独使用茜素磺酸钠作为指示剂进行硝酸钍滴定，在仔细规定的条件下通过分光光度法确定终点。 525 nm波长处的吸光度应达到任意值0.6。 也得到了 IUPAC 的批准。 [外文原描述]： The principle consists in separation of the fluorine from a test portion by distillation with sulphuric acid or perchloric acid. Titration with thorium nitrate solution using sodium alizarinsuphonate and methylene blue as indicators. Alternatively the thorium nitrate titration may be carried out using sodium alizarinsuphonate alone as indicator, the end-point being determined spectrophotometrically under carefully defined conditions. The absorbance at a wavelength of 525 nm shall reach the arbitrary value of 0.6. Has also been approved by the IUPAC.
英文名称Sodium fluoride for industrial use — Determination of fluorine content — Modified Willard-Winter method