ASTM D2194 – Concentration of Formaldehyde Solutions
Formaldehyde (CH2O, methanal) is a colorless, water-soluble substance with a strong odor. It is used extensively in organic and polymer synthesis, as a disinfectant and in biological applications. Proper usage often necessitates knowing the level of formaldehyde in starting materials. This test determines the level of formaldehyde, from 36 to 55%, in commercial solutions.
The sample is placed in an Erlenmeyer flask with a sodium sulfite solution and color indicator. The mixture is titrated with a standardized sulfuric acid solution to a colorless endpoint. The blank is accounted for and the percent formaldehyde is reported.