ISO 2833-1973 工业用氟化钠 氟含量的测定 威拉德-温特尔改进法

标准号：ISO 2833-1973
中文标准名称：工业用氟化钠 氟含量的测定 威拉德-温特尔改进法
英文标准名称：Sodium fluoride for industrial use; Determination of fluorine content; Modified Willard-Winter method
标准类型：G10
发布日期：1999/12/31 12:00:00
实施日期：1999/12/31 12:00:00
中国标准分类号：G10
国际标准分类号：71.060.50
适用范围：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.