Analysis of Plasticizer Contaminants in Beverages and Milk using an Automated System Based on Turbulent-flow Chromatography Coupled to LC-MS/MS

Significance of the Topic

Phthalates are widespread plasticizers that pose health and regulatory concerns when migrating into food and beverages.
Accurate, high-throughput detection methods are essential for ensuring compliance and consumer safety.

Objectives and Study Overview

This work introduces an automated inline method combining turbulent-flow chromatography with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify 11 plasticizers in drinks and milk.
The approach is validated over concentration ranges from 0.05 to 100 mg/L and assesses method performance in real matrices.

Methodology

Samples (250 µL) are spiked with 100 µL of deuterated internal standards, diluted to 1 mL with methanol, vortexed and centrifuged.
Online sample cleanup and preconcentration are performed using a TurboFlow C18 XL guard column, followed by separation on a Hypersil GOLD C18 analytical column under a 22-minute gradient.
Detection uses a TSQ Quantum Access Max triple quadrupole in positive electrospray mode with timed selected reaction monitoring of characteristic transitions.
Quantification relies on external calibration (zero to highest level) and deuterated standards for each analyte group.

Used Instrumentation

• Thermo Scientific Transcend TLX-1 system with TurboFlow™ technology
• TSQ Quantum Access Max triple quadrupole mass spectrometer
• TurboFlow C18 XL (0.5 × 50 mm) and Hypersil GOLD C18 (150 × 2.1 mm, 3 µm) columns
• Supporting lab equipment: centrifuge, vortex mixer, precision balances and automated pipettes

Main Results and Discussion

The method exhibited linearity (R² > 0.985) across target ranges for all 11 plasticizers.
Recoveries in orange juice, bitter lemon and milk ranged from ~70 % to 115 % with RSDs below 10 % for most compounds.
Limits of quantification reached as low as 0.05 mg/L, demonstrating the technique’s sensitivity and selectivity in complex matrices.

Benefits and Practical Applications

The fully automated workflow minimizes manual handling and cross-contamination, increasing throughput and reproducibility.
Suitable for routine quality control in food and beverage laboratories to monitor regulatory limits for phthalates.

Future Trends and Possibilities

Advancements may include coupling with high-resolution MS for non-target screening of emerging contaminants.
Further miniaturization and AI-based data processing could enhance sensitivity, reduce solvent consumption and streamline data review.

Conclusion

This TurboFlow LC-MS/MS method delivers rapid, reliable quantification of plasticizers in beverages and milk, fulfilling regulatory criteria while simplifying laboratory workflows.

References

Commission Decision 2002/657/EC on performance of analytical methods and interpretation of results.