Development of an analytical method for the determination of mineral oil aromatic hydrocarbons (MOAH) from printing inks in food packaging

An analysis method was developed to detect chemical markers of mineral oil aromatic hydrocarbons (MOAH) from offset printing inks in food packaging materials. 16 aromatic hydrocarbons were used as target analytes and different solid phase extraction procedures (SPE) and gas chromatography coupled to mass spectrometry (GC-MS) were tested. The concentration range studied was 0.1-7.5 µg g-1 with R2 higher than 0.9963, intraday RSD values below 5 %, RSD values between days lower than 12 %, recoveries higher than 80 %, LOD and LOQ lower than 0.09 μg g-1. Ten of the target analytes were identified in offset printing inks at concentrations between 2.28 and 8.59 µg g-1. Nine of them were also identified in the food packages examined in concentrations ranging from 0.10 to 0.33 µg g-1. These compounds were: methylnaphthalene, 2-methylnaphthalene, biphenyl, 2,6-dimethylnaphthalene, acenaphthene, 3,3',5,5'-tetramethylbiphenyl, 4,6-dimethyldibenzothiophene, 1-methylpyrene, benzo(b)naphtha(1,2-d)thiophene and 9,9'-dimethylfluorene. Mineral oil in food packaging was previously analysed by GC with flame ionization detection (FID).