Determination of mineral oil hydrocarbons

By Sabrina Ment, Dr. Claudia Schulz and Dr. Susanne Rathjen, Eurofins WEJ Contaminants, Germany

Currently, the main constituent of cardboard is recycled paper. During the process of recycling, mineral oils originating from inks used in newspaper printing may find their way into the cardboard. If food is packaged into cardboard boxes, such mineral oils can migrate into the food in relatively large quantities. Relevant food groups include rice, cereal flours, cereals, muesli, pasta, baking mixes, dried potato products and custard powder.

The mineral oil fraction of concern consists mainly of low molecular weight compounds (C16 up to C24), with the major portion being Mineral Oil Saturated Hydrocarbons (MOSH). About 15-20 % of the mineral oil fraction is composed of Mineral Oil Aromatic Hydrocarbons (MOAH).

In 2009 the German Federal Institute for Risk Assessment (BfR) issued a warning regarding the direct contact of large surface dry foods with recycled cardboard. Food packaging is subject to EU-Regulation 1935/2004 and must not be harmful to consumer health. The implementation of separate maximum levels for MOSH and MOAH originating from food packaging manufactured using recycled paper is currently under discussion in Germany.

Conventional GC-methods only allow for the quantification of the sum of MOSH and MOAH. A new online-HPLC-GC technique enables now the separate quantification of MOSH and MOAH within one chromatographic run. Separation and clean-up of MOSH- and MOAH-fractions is achieved using normal-phase HPLC. Subsequently, the simultaneous transfer of both fractions to a dual-channel gas chromatographic system with two different separation columns and flame-ionization detection (GC-FID) allows for the separate quantification of MOSH and MOAH (fig. 1).

Eurofins WEJ Contaminants established this groundbreaking technique and is able to offer the simultaneous determination of MOSH and MOAH from food products.

Contact: DagmarHegemann@eurofins.de