Analysis of Additives in Food Containers Using LCMS-9030 Quadrupole Time-of-Flight Liquid Chromatograph Mass Spectrometer

Significance of the Topic

Polymer additives such as antioxidants, ultraviolet absorbers and flame retardants play a central role in enhancing the mechanical performance, durability and safety of plastic and rubber materials used for food contact applications.
Accurate qualitative and quantitative assessment of these additives is essential to ensure product quality, regulatory compliance and consumer protection.

Objectives and Study Overview

This study aimed to establish an integrated workflow for the qualitative identification and precise quantification of multiple polymer additives in food container materials using a high-resolution quadrupole time-of-flight liquid chromatograph mass spectrometer.
Five different types of food contact containers (packs and films) were analyzed to evaluate the occurrence and concentration profiles of fourteen common additive components.

Methodology and Used Instrumentation

Sample Preparation:

• Extraction of 0.1 g finely chopped container material with tetrahydrofuran by 1 min sonication.
• Addition of methanol, filtration through a 0.2 μm membrane and dilution for analysis.

Instrumental Analysis and Data Processing:

• Shimadzu LCMS-9030 quadrupole time-of-flight mass spectrometer operated in positive and negative electrospray ionization modes.
• Shimadzu high-performance liquid chromatograph with Kinetex® XB-C18 column (75 mm × 2.1 mm I.D., 2.6 μm) using a 10 mmol/L ammonium formate water/methanol gradient at 0.5 mL/min and 40 °C.
• LabSolutions Insight Explore software for peak picking and compositional formula estimation.
• ACD/MS Structure ID Suite for offline database searching and fragment-based ranking from the PubChem library.
• Confirmation of compound identity by comparing retention time and MS/MS spectra with authentic standards.

Main Results and Discussion

Identification:
Peaks at m/z values of 637.4941, 386.3057, 1194.8190, 548.5039 and 647.4591 corresponded to known additives including Irganox® 1098, CYANOX® 425, Irganox® 1010, Irganox® 1076 and Irgafos® 168. Composition estimation of peak X (m/z 637.4941) yielded C40H64N2O4, and database ranking identified Irganox® 1098, confirmed by matching MS/MS spectra to the standard.

Quantitative Analysis:
Calibration curves for fourteen additives covered ranges from 0.01 to 1000 ppb with coefficients of determination (R2) above 0.993.
Quantification in five container samples revealed additive levels from non-detectable to several hundred milligrams per gram, with Irgafos® 168 measured between 1.85 and 799.66 ppb in diluted extracts and 37 to 800 mg/g in solid materials.

Discussion:
The high mass accuracy and resolution of the QTOF system enabled selective detection of target ions with reliable structural assignment, even in complex polymer matrices.

Benefits and Practical Applications

The developed workflow provides a streamlined route from initial screening to exact quantification of polymer additives, offering:

• High selectivity in complex sample backgrounds.
• Rapid structural elucidation without exhaustive sample cleanup.
• Robust quantitation for quality control, material development and regulatory compliance.

Future Trends and Potential Applications

Advances in real-time data processing and expanded spectral libraries are expected to accelerate compound identification.
Machine learning algorithms may automate MS/MS interpretation and improve fragment prediction accuracy.
Integration with ambient ionization techniques could enable direct surface analysis of polymers with minimal preparation.
Development of comprehensive databases for emerging additives and degradation products will enhance monitoring capabilities.

Conclusion

An end-to-end analytical strategy combining high-resolution LC-QTOF MS, advanced data processing and database searching was successfully implemented for comprehensive analysis of polymer additives in food containers.
This approach demonstrates strong potential for routine use in quality assurance, research and development of improved polymer formulations.