Untargeted Mass Spectrometry Screening for Polyolefin Recyclate Compliance
High-resolution mass spectrometry screening paired with surrogate semi-quantification establishes food-contact compliance for post-consumer polyolefins.
Antioxidant Transformation Products
Meaning
Sacrificial degradation of polymer stabilizers during melt processing generates several distinct chemical species. In analytical screening of extractables, these substances are classified as antioxidant transformation products. They arise when primary or secondary stabilizers react with peroxy radicals and hydroperoxides to protect the polymer matrix.
Because these chemical species migrate into packaged products, understanding their behavior is necessary for long-term safety evaluation.
Degradation Pathway
Thermo-oxidative stress during compounding and injection molding breaks down phosphite stabilizers into oxidised phosphates. These specific pathways determine the final chemical structure of the degradants. When melt temperature increases, the concentration of these products rises.
Chromatographic Extraction
Extracting these non-intentionally added substances requires specific solvent extraction followed by liquid chromatography coupled with mass spectrometry. Analysts utilize methanol or hexane to isolate the degraded species from the polyolefin matrix. The recovery rate depends heavily on the swelling of the polymer network.
Solvent selection prevents the thermal degradation of the remaining active additives during the test.
Food Contact Compliance
Regulatory bodies require the evaluation of all migrating substances below specific toxicological thresholds. Standardized migration trials establish the concentration of the chemical species in food simulants. If the total migration level exceeds safe thresholds, the converter must adjust the stabilizer package or the processing temperature.
This measurement ensures that the packaging complies with direct-contact health guidelines.