Determination of 24 primary aromatic amines in aqueous food simulants by combining solid phase extraction and salting-out assisted liquid–liquid extraction with liquid chromatography tandem mass spectrometry

Abstract

Carcinogenic primary aromatic amines (PAAs) can be released from improperly manufactured food packaging materials. The limit for the sum of PAAs is set to 10 µgkg−1 in Commission Regulation No. 10/2011 (FCM Regulation). However, a lower individual limit, 2µgkg−1 has been recently introduced for the carcinogenic PAAs in Commission Regulation No. 2020/1245. As the majority of the previously published methods are no longer compliant with the current regulation, a UHPLC-MS/MS method was developed to enable food packaging compliance testing for PAAs not only from 3% (w/v) acetic acid, but also from 10% (v/v) ethanol food simulant. Since the latest amendment of the FCM Regulation refers to the list of the 22 restricted PAAs of EU Regulation No. 1907/2006, these PAAs were selected as target compounds along with aniline and p-toluidine, the most common impurities of azo colorants and isocyanates. An enrichment factor of 20 could be achieved combining solid phase extraction with salting-out assisted liquid–liquid extraction. The method was successfully validated and applied on real samples. Limit of quantitation (LOQ) and limit of detection (LOD) values were 0.15µgL−1 and 0.05µgL−1 for both food simulants, respectively; except for 2,4-diaminotoluene, aniline and 4,4′-oxydianiline. However, even these compounds had lower LOD values than the new individual limit of 2 µgkg−1. Cumulative LOD values for both food simulants (1.6µgL−1 and 1.5 µgL−1 for 3%(w/v) acetic acid and 10% (v/v) ethanol, respectively) were lower than the 10µgkg−1 specified in the FCM Regulation. Accuracy values were between 70 and 118% for both food simulants for the majority of PAAs. Both within-day and between-day precision values were below 20%. This method proved to be suitable for daily routine analysis enabling compliance testing of food packaging materials according to the latest regulations. The method was successfully applied for the analysis of plastic kitchenware samples.