Abstract:

The conditions for color reaction of acetylacetone and formaldehyde and conversion of hexamethylenetetramine (HMTA) to formaldehyde were optimized. An acetylacetone spectrophotometric method was proposed for the determination of migration of formaldehyde and HMTA from plastic to acetic acid solution. The linear range of calibration curve was 0－15 mg/L, and the detection limit for the method was 0.09 mg/L. The conversion rate of HMTA to formaldehyde was 98.3%－100% and the recovery for formaldehyde in HMTA solution was 99.5%－101%. A collaborative trial was carried out by nine laboratories to samples with formaldehyde levels of 9.93 mg/L (containing HMTA) and 7.01 mg/L (without HMTA). The repeatability limits were 0.707 and 0.112 mg/L and the reproducibility limits were 2.094 and 1.516 mg/L, respectively.

Key words: formaldehyde, hexamethylenetetramine, acetylacetone, spectrophotometry, plastics, migration