Study of melamine and formaldehyde migration from melamine tableware

Two HPLC-UV rapid methods have been developed to quantify and identify melamine, ammeline, ammelide and formaldehyde in samples of melamine plastic kitchenware. Eighteen samples of melamine articles purchased at various markets in Galicia (Spain) and Quito (Ecuador) were analyzed. Melamine analysis was carried out using a HILIC column (150 x 3 mm, 3 A mu m size of particle) and ammonium formate 10 mM (fitted to pH 3 with formic acid)/acetonitrile (5:95 v/v) as mobile phase. Formaldehyde was reacted with 2,4-dinitrophenylhydrazine, and then the analysis was carried out using a Kromasil ODS (C18) column (150 x 3.20 mm, 5 A mu m size of particle). A gradient elution method was applied using Milli-Q water and acetonitrile as mobile phase. Articles were exposed to the food simulant acetic acid 3 % (w/v). The test conditions used were repeated exposures to the simulant for 2 h at 70 A degrees C. The methods were validated with respect to linearity, limits of detection and quantification, and repeatability. Melamine migration was detected in 8 of the 18 food contact articles analyzed. However, none of the samples exceeded the specific migration limit (SML) of 2.5 mg/kg on the third exposure. Ammeline and ammelide were not detected in any sample. Formaldehyde migration was detected in all of the samples analyzed, and in 56 % of the samples, formaldehyde levels were above the SML of 15 mg/kg established in European Regulation.