Abstract
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.
Read sample
Preview this standard in our Online Browsing Platform (OBP)
General information
Life cycle
Got a question?
Check out our FAQs
Customer care
+41 22 749 08 88
Opening hours:
Monday to Friday - 09:00-12:00, 14:00-17:00 (UTC+1)