Optimization of pressurized liquid extraction (PLE) for rapid determination of mineral oil saturated (MOSH) and aromatic hydrocarbons (MOAH) in cardboard and paper intended for food contact

Packaging can represent a primary source of food contamination with mineral oil saturated hydrocarbons (MOSH) and aromatic hydrocarbons (MOAH), especially when recycled cardboard or mineral oil based printing inks are used. A pressurized liquid extraction (PLE) method, followed by on-line LC–GC analysis, has been optimized for rapid mineral oil determination in cardboard and paper samples. The proposed method involves extraction with hexane (2 cycles) at 60 °C for 5 min, and allows for the processing of up to 6 samples in parallel with minimal sample manipulation and solvent consumption. It gave good repeatability (coefficient of variation lower than 5%) and practically quantitative extraction yield (less than 2% of the total contamination found in a third separate cycle). The method was applied to different cardboards and paper materials intended for food contact. Results obtained were similar to those obtained by applying classical solvent extraction with hexane/ethanol 1:1 (v/v) as described by Lorenzini et al. [20].