ISO 2227:1972

Formaldehyde solutions for industrial use — Determination of formaldehyde content

The specified method is applicable to HCHO contents between 25 5 and 45 %. The field of application may be extended by siutably modifying the mass of the test portion. The principle consists in the reaction of the test solution with a neutral sodium sulphite solution, and acidimetric titration of the liberated sodium hydroxide in presence of thymolphthalein as indicator.