Hydrocarbon Quantification
Chromatography protocols determine the total content of mineral oil saturated hydrocarbons and mineral oil aromatic hydrocarbons within a packaging substrate or food contact material. High performance liquid chromatography coupled to gas chromatography with flame ionization detection serves to isolate these fractions from complex mixtures. Experts extract residues through solvent migration simulation or direct dissolution to map mass distribution across specified carbon chain lengths.
This method quantifies potential contaminants that migrate from paperboard made with recycled fibres or printed with offset inks. Limits for these substances prevent ingestion of toxic mineral oil residues.
Extraction Procedure
Laboratories prepare samples by cutting substrates into small pieces to increase surface area for solvent contact. Hexane or ethanol based solvents extract the saturated and aromatic compounds from the fibrous matrix during a controlled agitation cycle. Clean up steps remove interfering natural waxes or binders to ensure the analytical signal originates solely from the mineral oil fractions.
Analysts inject the resulting extract into the column where separation occurs based on boiling point and polarity. Detectors quantify the amount of hydrocarbon present by measuring current generated during combustion of the eluent. Internal standards verify recovery efficiency and compensate for losses during the preparation phase.
The resolution of the column identifies specific clusters representing the saturation levels of the hydrocarbon chains. Automated integration software calculates the area under the peaks to convert current pulses into mass concentrations.
Regulatory Limit
Compliance requires adherence to strict migration thresholds established for food safety to prevent chemical leakage into sensitive products. Converters monitor these levels when sourcing secondary fibre or when formulating printing chemistries for primary food packaging. Elevated readings in the aromatic fraction trigger an immediate investigation of ink supply chains and board decontamination treatments.
Proper verification of low volatility prevents long term accumulation of harmful compounds within the human body. Stringent testing protocols effectively block high risk materials from entering the manufacturing cycle.
