Phthalate Screening in Food Packaging by Ambient Ionization High Resolution MS/MS Mass Spectrometry

Importance of the Topic

Phthalic acid diesters are commonly used as plasticizers in food packaging and consumer goods and pose health risks due to their endocrine disrupting properties and potential carcinogenicity. Rapid detection in packaging is essential to ensure safety and regulatory compliance.

Objectives and Study Overview

This work aims to establish a fast, ambient ionization high‐resolution MS/MS screening method for phthalate contaminants in food packaging materials. The study compares full‐scan and MS2 fragmentation patterns of standard phthalates with those obtained directly from packaging samples.

Methodology and Instrumentation

A Direct Analysis in Real Time (DART) SVP ion source was coupled to a Q Exactive Orbitrap mass spectrometer.

• DART conditions: 200 °C, helium gas, stainless steel mesh sample holders.
• Mass analyzer: Orbitrap with m/z range 100–1000, resolving power 140 000, AGC targets of 1e6 (full scan), 1e5 (SIM), and 2e5 (MS2).
• Acquisition modes: full‐scan MS, selected ion monitoring (SIM), and MS2 via higher energy collision dissociation (HCD) at normalized collision energy of 10 arb.u.
• Method duration: 1.2 minutes per sample with initial background acquisition of 0.3 minutes.

Main Results and Discussion

The approach enabled unambiguous identification of phthalate diester isomers by accurate mass and characteristic HCD fragmentation fingerprints. Screening of 48 commercial items (including lid gaskets, milk packages, bags, containers, shoes, wallets, and sports equipment) required under 2 minutes per sample. No banned phthalates were detected above background levels, while common polymer additives such as ATBC, DEHA, AcPG, and erucamide were identified. Ambient phthalate background was managed by pre‐acquisition monitoring to avoid false positives.

Benefits and Practical Applications

• Elimination of sample preparation reduces contamination and analysis time.
• Full‐scan MS/MS provides comprehensive screening and structural confirmation in a single run.
• The rapid workflow (<2 min/sample) enhances throughput in quality control labs.
• Adaptable to various consumer goods beyond food packaging.

Future Trends and Potential Applications

Future developments include the preparation of solid standards with defined phthalate ratios for quantitative analysis, integration of advanced ambient ion sources for lowered background, and application to broader classes of semi‐volatile organic contaminants in regulatory and industrial settings.

Conclusion

The DART-Orbitrap HRMS/MS screening method offers a fast, sensitive, and reliable tool for detecting phthalate plasticizers in food packaging. By combining full-scan accurate mass data with MS2 fragmentation, the workflow ensures robust identification while minimizing sample preparation and contamination.

Reference

• [1] FDA docket: www.fda.gov/ohrms/dockets/dailys/02/Dec02/120502/02d-0325-c000018-02-vol1.pdf; [2] Kamrin MA; J Toxicol Environ Health B Crit Rev, 2009, 12(2):157-74; [3] Self RL et al.; Food Control, 2012, 25:13-16; [4] Rothenbacher T., Schwack W.; Rapid Commun Mass Spectrom, 2009, 23:2829-2835; [5] Kuki A et al.; Int J Mass Spectrom, 2011, 303:225-228.