Selective Extraction And Analysis of Chemical Migrants from Packaging Material using Supercritical Fluids (SFE)

Importance of the Topic

The analysis of chemical migrants from packaging materials is critical for ensuring product safety, regulatory compliance and consumer health. Migrants, including extractables and leachables, can affect pharmaceutical formulations, food quality and cosmetic products. Advanced extraction and analysis techniques help laboratories reduce solvent use, shorten analysis time and improve selectivity.

Objectives and Overview of the Study

This study compared three extraction methods—microwave, Soxhlet and supercritical fluid extraction (SFE)—to profile chemical migrants from common packaging polymers. The goal was to evaluate solvent consumption, extraction speed and compatibility with ultraperformance convergence chromatography (UPC²) coupled to detectors for routine screening of additives and contaminants.

Methodology

Samples of high-density polyethylene (HDPE), low-density polyethylene (LDPE), ethylene vinyl acetate (EVA) and polyvinyl chloride (PVC) were prepared as 1 cm² pieces. Target analytes included phosphite and phenolic antioxidants, benzophenone UV stabilizers, plasticizers and hindered amine light stabilizers. Extractions were performed under the following conditions:

• Microwave: 2 g sample, 10 mL hexane or isopropanol, 50 °C, 3 h
• Soxhlet: 5 g sample, 175 mL hexane or isopropanol, 50 °C, 8 h
• SFE: 2 g sample, CO₂ with 2–20 % isopropanol co-solvent, 50 °C, 300 bar; static (2×20 min) and dynamic (10–30 min) modes

Used Instrumentation

The automated MV-10 SFE system was employed for supercritical extractions. Analytical separations utilized the ACQUITY UPC² system with a column manager, make-up pump, backpressure regulator and split flow to photodiode array and mass spectrometry (single quadrupole or tandem MS) detectors. CO₂ and isopropanol were delivered by dedicated pumps, and temperature control was maintained via a thermoelectric heat exchanger.

Results and Discussion

All three extraction techniques yielded comparable profiles of extractables, but SFE consumed 90 % less solvent and completed within an hour versus 8–72 h for other methods. UPC² analysis achieved baseline separation of ten target compounds in four minutes, compared to 9.5 min by UPLC, demonstrating orthogonality and high throughput. Identification of antioxidants Irgafos 168, Irganox 1010 and Irganox 1076 in LDPE extracts was confirmed by mass spectra matching retention times and m/z values.

Practical Benefits and Applications

• Rapid method development and high selectivity via modifier composition and pressure tuning
• Reduced laboratory costs and environmental impact due to minimal organic solvent use
• Compatibility with diverse sample diluents and detectors for qualitative and quantitative analysis
• Lower extraction temperatures protect thermally labile analytes

Future Trends and Opportunities

Continued integration of automated SFE with high-resolution MS and data analytics will advance screening of packaging migrants. Emerging co-solvent systems and pressure–temperature optimization will expand polarity ranges. Standardized SFE-UPC² workflows are poised to become reference methods for regulatory compliance in pharmaceutical, food and cosmetic industries.

Conclusion

Supercritical fluid extraction paired with UPC² offers a fast, green and highly selective approach for profiling packaging migrants. The combination reduces solvent consumption, shortens analysis time and delivers high-resolution separations, making it an attractive alternative to traditional extraction and chromatography techniques.