Validation of a liquid chromatography–mass spectrometry method for determining the migration of primary aromatic amines from cooking utensils and its application to actual samples

Abstract

Many cooking utensils are made of nylon, a material that may incorporate azodyes and where primary aromatic amines (PAAs) are the starting substances. Moreover, aromatic amines may also be present as technical impurities. Another source of PAAs could be aromatic isocyanates used as monomers in the production of polyurethanes. The aim of this work was to validate a simple LC–MS/MS method for the determination of eight primary aromatic amines (m-phenylenediamine, 2,6- and 2,4-toluenediamine, 1,5-diaminonaphthalene, aniline, 4,4′-diaminonaphenylether, 4,4′-methylenedianiline and 3,3′-dimethylbenzidine) in the aqueous food simulant 3% acetic acid (w/v). The detection limits calculated were adequate with respect to present legislation. The method was validated at four concentration levels (2, 5 10 and 20 µg kg⁻¹). Global internal reproducibility was in the range 5.6–21.4% (RSD_R) depending on the compound and concentration. Mean recoveries for all levels varied between 89 and 100%, depending on the amine. A total of 39 samples of cooking utensils were analyzed using the described method and the results obtained after the third migration test were not compliant in approximately half of the samples.

Keywords:

• chromatography, LC/MS
• method validation
• food contact materials
• food simulants
• migration

Acknowledgements

The contents of this paper are the responsibility of the authors alone and should not be taken to represent the opinions of the supporting organizations. Authors are grateful to the “Angeles Alvariño” Program financed by “Consellería de Innovación e Industria, Xunta de Galicia” for the postdoctoral contract of R. Sendón. The authors are grateful to Carmen Tejedor Román and Libertad García Martín for their excellent technical assistance.