Analytical Principle
Separation and detection of volatile organic compounds represent the standard method for quantifying mineral oil residues in paper packaging. When employing gas chromatography flame ionization, the vaporized sample is separated by boiling point on a capillary column before entering a hydrogen flame. The combustion of organic molecules produces ions that generate an electrical current.
This current is measured to quantify the mass of the substances.
Quantitative Precision
Reliable quantification of complex mixtures like mineral oils requires a stable detector response over a wide molecular range. The gas chromatography flame ionization system provides a highly linear response that is ideal for measuring the unresolved complex mixtures of saturated and aromatic hydrocarbons. Unlike mass spectrometry, it does not suffer from varying ionization efficiencies across different hydrocarbon classes.
This stability makes the detector the primary tool for certifying that food contact paperboard complies with migration limits. It gives converters a dependable baseline for barrier evaluation.
Sample Preparation
Analysis begins with the extraction of the hydrocarbons from the paperboard using organic solvents. After extraction and cleanup, the sample is injected into the gas chromatography flame ionization instrument. The injector temperature must be high enough to volatilize the heavy hydrocarbon fractions without causing thermal degradation of the paper extracts.
