標準號：ISO 4281-1977
中文標準名稱：工業用六氟硅酸鈉 游離酸度和六氟硅酸鹽總含量的測定 滴定法
英文標準名稱：Sodium hexafluorosilicate for industrial use; Determination of free acidity and total hexafluorosilicate content; Titrimetric method
標準類型：G10
發布日期：1999/12/31 12:00:00
實施日期：1999/12/31 12:00:00
中國標準分類號：G10
國際標準分類號：71.060.50
適用范圍：With respect to the free acidity, applicable to products having contents, expressed as H2 SiF6 , equal to or more than 0,1 % (m/m). First, determination of the free acid contents by titration of an ice-cooled test portion with a standard volumetric sodium hydroxide solution in the presence of potassium nitrate and using bromothymol blue as indicator, then, followed by titration at near boiling temperature with standard volumetric sodium hydroxide solution to the appearance of a permanent blue colour.