Developed test method of migration of formaldehyde and hexamethylenetetramine from platics into food simulants by spectrophotometry with chromotropic acid

The conditions in the color reaction of chromotropic acid with formaldehyde and conversion of hexamethylenetetramine(HMTA) to formaldehyde were studied and optimized.A spectrophotometry with chromotropic acid has been developed for the determination of migration of formaldehyde and HMTA(as formaldehyde)in acetic acid solution.The linear range of calibration curve is 0～15 mg/L,and the detection limit of the method is 0.17 mg/L.The conversion rate of HMTA to formaldehyde is(99.5～100)%.A collaborative trial was caryyed out by eight laboratories with samples having level of 10.3 mg/L(containing HMTA) and of 7.28 mg/L(without HMTA).The repeadility limit are 0.434 and 0.159 mg/L,and the reproducibility limit are 2.487 and 1.707 mg/L,respectively.