GB/T 29493.5-2013 Determination of harmful substances in textile dyeing and fininshing auxiliaries—Part 5:Determination of free formaldehyde in emulsion polymers
This part of GB/T 29493 specifies the method for determination of free formaldehyde in emulsion polymer of textile dyeing and finishing auxiliaries.
This part is applicable to the determination of trace free formaldehyde (including the free formaldehyde released after hydrolysis) in emulsion polymers of textile dyeing and finishing auxiliaries (mainly acrylate, acrylonitrile-butadiene, carboxylated styrene-butadiene, polyvinyl acetate, vinyl acetate-acrylate, styrene-acrylates, fluorine-containing acrylate polymers like water and oil proofing agents).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the normative document (including any amendments) applies.
GB/T 2912.1-1-2009 Textiles - Determination of formaldehyde - Part 1: free and hydrolyzed formaldehyde (water extraction method)
GB/T 6682-2008 Water for analytical laboratory use - specification and test methods
GB/T 8170-2008 Rules of rounding off for numerical values & expression and judgment of limiting values
3 Principle
The formaldehyde in the sample may have a reaction with a derivatization reagent 2,4-dinitrophenylhydrazine to produce a 2,4-dinitrophenylhydrazone with ultraviolet absorption capacity. High-performance liquid chromatography is employed to detect at 353 nm with a UV detector or a diode array detector. The content of formaldehyde content in the sample is calculated with reference to the standard working curve. Below is the reaction formula:
