Validation and application of an LC-MS/MS method for the determination of cyclic oligomers originating from polyamide 6 and polyamide 66 in food simulant.

Polyamides (PAs) are used in the production of various food contact materials (FCMs) and articles such as kitchen utensils and packaging material. Cyclic oligomers have been identified as potential migrants from PA. This study describes the development, validation and application of a multi-oligomer analytical method based on LC-ESI-MS/MS for the identification and quantification of eight cyclic oligomers of PA 6 and four PA 66 migrating from FCMs into food simulant B (3% acetic acid) and beverages. It was proved that doubly charged precursor ions of the cyclic PA 6 and PA 66 oligomers above a mass of 500 Da are formed during the ionisation process of the electrospray technique used. Direct injection of a diluted food simulant into the LC-ESI-MS/MS system after migration makes the validated method a valuable tool for investigating migration of cyclic PA oligomers. The validation results demonstrate that the multi-oligomer method is applicable for the analysis of cyclic PA 6 and PA 66 oligomers in food simulant B. For all investigated cyclic PA oligomers, detection limits were in the range of 0.1-1.1 µg/l. Linearity (r2 ≥ 0.99), trueness values between 91% and 122%, and intra-day (RSDr < 10%) and inter-day precision (RSDR < 19%) were determined and satisfied validation criteria set out by the European Reference Laboratory for FCMs. The method was extended to tap water and tea. Finally, the multi-oligomer method was successfully applied to determine cyclic PA oligomers in migration solutions originating from different PA FCMs. In all migration solutions, concentrations of cyclic PA oligomers were determined above the LOQ. A preliminary risk assessment based on in silico tools was performed. The results demonstrate the urgent need for toxicological data that would facilitate the evaluation of the health risk of cyclic PA oligomers.

Transfer of primary aromatic amines from coloured paper napkins into four different food matrices and into cold water extracts.

The aim of this study was to compare the transfer of primary aromatic amines (PAAs) from napkins into cold water extract (CWE) with transfer into four different food matrices. An HPLC-MS/MS multi-analyte method for quantification of 26 PAAs in CWE was validated and applied. In addition, the method was validated for seven different PAAs in four different food matrices (cucumber, rice, pickled gherkin and butter cookie) representing wet, dry, acidic and fatty food. The CWEs of 12 coloured napkin samples were analysed, and 3 napkins released more than 0.01 mg kg-1 PAAs into the CWE. These three napkins were chosen for transfer testing with food samples. In total, seven different PAAs were quantified in the food samples. Results show that the transfer of the tested PAAs into the CWE is in most cases comparable to the transfer into the tested food samples. In some cases, the CWE overestimates transfer into food, except for the transfer of aniline into pickled gherkin, where the CWE underestimates transfer. Therefore, the CWE serves as an adequate and certainly not overestimating simulation of reality for the tested transfer of PAAs into the food samples.

N-nitrosamines migrating from food contact materials into food simulants: analysis and quantification by means of HPLC-APCI-MS/MS.

It was the aim of the work described here to develop a validated analytical method for the determination of N-nitrosamines in food simulants. Here, we present the validation of a liquid chromatography-atmospheric pressure chemical ionisation-tandem mass spectrometry method for the determination of 13 N-nitrosamines in the food simulants deionised water, 3% acetic acid and 10% ethanol. Method validation encompassed linearity, LOD, LOQ, recovery, precision and stability of the N-nitrosamines. The method was found to be sufficiently rugged and suitable for routine analysis. In addition, the developed method is on average 10 times more sensitive than the gas chromatography-thermal energy analyser (GC-TEA) method that is currently stipulated in Recommendation XXI for commodities based on natural and synthetic rubber issued by the German Federal Institute for Risk Assessment (BfR). The developed method was applied to determine the N-nitrosamine contents in migration solutions of 12 elastomer samples covering a range of different elastomer types. In 10 out of 12 samples, N-nitrosamines were determined. In most samples, the guidance value of 1 µg/dm2 specified in BfR Recommendation XXI was not exceeded. In conclusion, the analytical method presented here offers a useful alternative to the GC-TEA method currently stipulated in BfR Recommendation XXI. This is of wider relevance, since BfR recommendations are used for compliance assessment of Article 3, paragraph 1 a of the Regulation (EC) No. 1935/2004 with respect to their health safety.

Inter-laboratory comparison study on the determination of primary aromatic amines in cold water extracts of coloured paper napkins.

To evaluate the competence in the analysis of primary aromatic amines (PAAs) in cold water extracts from napkins, an inter-laboratory comparison study was conducted with 19 participating laboratories. Two cold water extracts spiked at two different PAA concentration levels, each containing four different PAAs (aniline, o-toluidine, 2,4-dimethylaniline and o-anisidine) and, additionally, four different napkins containing one of the PAAs each were distributed between the laboratories. In this exercise, the influence of different parameters in the preparation of cold water extracts from napkins according to the European Norm (EN) 645 was also investigated. For the already spiked cold water extracts and the napkins, 88% and 77% of the results were satisfactory with zU-scores of ≤ |2|. The Horwitz ratio (HorRat) values for the spiked cold water extracts were in the range of 0.48-1.25. For the napkins, HorRat values were in the range of 1.261.91, whereas the lowest assigned value was 0.97 µg l(-1) (o-toluidine). Thus, the results show that preparation and instrumental analysis of PAAs in cold water extracts from napkins according to EN 645 has been well established.