Mineral Oil Analysis in Recycled Fibre Food Packaging
Verify MOSH and MOAH compliance in recycled fibre packaging using accredited HPLC-GC-FID testing, validated functional barriers, and complete declarations of compliance.
POSH Interference
Overlap Mechanism
Synthetic polyolefin materials release low molecular weight branched and cyclic oligomers during manufacturing and thermal processing steps. Polyolefin oligomeric saturated hydrocarbons co-elute with mineral oil saturated hydrocarbons during gas chromatography testing. POSH interference occurs when synthetic oligomers originating from polyethylene or polypropylene coatings mask the analytical quantification of mineral oil residues in packaging extracts.
Liquid chromatography pre-fractionation fails to separate polyolefin oligomers from mineral oil saturated hydrocarbons due to structural similarity. High temperature gas chromatography with flame ionization detection records broad overlapping chromatogram humps that obscure true hydrocarbon contamination levels.
Separation Boundary
Packaging materials containing extrusion-coated polyolefins or synthetic adhesive layers release branched alkanes during extraction with organic solvents like hexane. Hydrocarbon oligomers exhibit mass spectrometry fragmentation patterns similar to mineral oil fractions, hindering clear compound identification. Minimizing POSH interference requires comprehensive knowledge of raw material packaging formulations alongside advanced mass spectrometry screening techniques.
Solid phase extraction techniques or specialized silica gel column chromatography assist in separating natural biogenic interferences but struggle to isolate polyolefin oligomers. Misinterpreting oligomeric humps leads to overreporting mineral oil saturated hydrocarbon levels in packaging compliance reports.
Mass Quantification
Regulatory authorities enforce distinct chemical threshold limits for mineral oils compared to synthetic polyolefin oligomers. Overestimating mineral oil contamination causes false compliance failures for fully safe barrier-coated paperboard packaging. POSH interference defines a major analytical challenge in food contact material compliance verification.