Waters Application Notes - Food Testing

Importance of Monitoring Primary Aromatic Amines (PAAs)

Primary aromatic amines are recognized genotoxic impurities that may migrate from polyamide kitchenware into foodstuffs. Chronic exposure to PAAs such as aniline and related compounds poses health risks and is subject to strict regulatory limits in the EU (rim migration limit 0.01 mg/kg). Reliable analytical methods are essential for both official public health control and industry due diligence.

Objectives and Scope

This study aimed to develop and validate a fast, sensitive, and robust UPLC–MS/MS method for the quantification of 23 PAAs in polyamide kitchenware migration extracts. The method needed to meet EU regulatory requirements for limits of quantification (LOQs) well below the maximum allowed migration levels and to provide high throughput and minimal maintenance.

Methodology and Sample Preparation

• Migration testing: Kitchenware specimens were exposed to food simulants (water, 3% acetic acid, 15% ethanol, and olive oil) at 60 °C for 10 days to extract diffused PAAs.
• SPE cleanup: Extracts were passed through Oasis PRiME HLB cartridges to remove matrix interferences (phospholipids, fats), enabling direct analysis without ion-pairing reagents.
• Calibration and QC: Matrix-matched calibration curves were prepared from 0.005 to 5 µg/L for each PAA, and quality control spikes were analyzed at low, medium, and high levels to assess accuracy and precision.

Instrumentation

• LC: ACQUITY UPLC I-Class System with ACQUITY UPLC BEH Amide column (1.7 µm, 2.1 × 100 mm), mobile phases of 0.1% formic acid in water and in acetonitrile.
• MS/MS: Xevo TQ-S micro tandem quadrupole mass spectrometer, ESI+, optimized multiple reaction monitoring (MRM) transitions for all 23 PAAs.

Results and Discussion

• Limits of quantification: LOQs of 0.005 mg/kg in migration tests (equivalent to 5 µg/L) were achieved for all target PAAs, well below the EU limit of 0.01 mg/kg.
• Linearity and precision: Matrix-matched calibration curves showed R² > 0.995. Recoveries ranged between 75% and 120% with repeatability (RSD) < 10% across all compounds.
• Matrix effects: SPE cleanup reduced phospholipids and fat interferences by > 95%, resulting in matrix effects < 15% for all analytes without needing ion-pairing reagents.

Practical Implications

The validated method provides a streamlined workflow for routine screening of PAAs in kitchenware migration studies. Its single-injection protocol, minimal maintenance requirements, and high sensitivity support both regulatory compliance testing and industry quality control.

Future Trends and Opportunities

• High-throughput automation: Integration with robotic sample handling for large volume testing and further reduction in sample-prep time.
• Expanded spectral libraries: Inclusion of emerging contaminants and non-targeted screening capabilities using high-resolution mass spectrometry.
• Online cleanup: Development of on-line SPE–LC coupling to further streamline workflows and reduce solvent usage.

Conclusion

A rapid and robust UPLC-MS/MS method using Oasis PRiME HLB cleanup and Xevo TQ-S micro detection was successfully developed for quantifying 23 primary aromatic amines in polyamide kitchenware migration extracts. The method meets EU requirements with LOQs well below regulatory limits, high recoveries, precise quantification, and minimal matrix interference.

References

• CEN/TS 13130-20: Food contact materials—Determination of primary aromatic amines. European Committee for Standardization.
• European Commission. Regulation (EU) No 10/2011 on plastic materials and articles intended to come into contact with food.
• European Union SANTE/11945/2015 Guidance Document on Analytical Quality Control and Method Validation Procedures for Pesticides Residues in Food and Feed.
• Waters Application Note 720005550EN. Analysis of PAAs Using Oasis PRiME HLB Cartridges for Sample Cleanup, May 2016.