Analytical Chromatography
High-resolution instrument systems that vaporize complex mixtures and separate their components through a column are essential for identifying trace chemical compounds in packaging materials. Packaging chemists utilize gas chromatography flame ionization detection to measure the migration of volatile and semi-volatile organic compounds from recycled paperboard. It works by burning the separated compounds in a hydrogen flame, which generates ions that produce an electrical current proportional to the concentration of the organic carbon.
Detector Operation
The sample is first extracted from the paperboard using a solvent or collected via headspace heating, before being injected into the carrier gas stream of the instrument. As the gaseous mix moves through the heated column, different molecules travel at varying speeds based on their boiling points and chemical affinities. Upon exiting, the compounds enter a micro-burner where the resulting ionization is measured by an electrometer.
This response is plotted over time to create a chromatogram, allowing the laboratory to quantify specific mineral oil saturated hydrocarbons and aromatic hydrocarbons.
Compliance Verification
Safety regulations for food contact materials demand that migrant chemical levels remain below strict toxicity thresholds. Recycled boxboard often contains inks and adhesives from the feed stream that must not migrate into the food. This highly sensitive flame detection method provides the quantitative data required to prove that a barrier coating is performing correctly and that the package complies with food safety standards.
