Analysis of benzophenone and 4-methylbenzophenone in breakfast cereals using ultrasonic extraction in combination with gas chromatography-tandem mass spectrometry (GC-MS)

Benzophenone (BP) and 4-methylbenzophenone (4MBP) are photo-initiators that are generally used to cure ink on carton boards.In this contribution, a fast and reliable method for the determination of BP and 4MBP in breakfast cereals is described. The sample was extracted ultrasonically using a mixture of dichloromethane and acetonitrile (1:1), followed by a clean-up of the extract using solid phase extraction with a silica cartridge. Finally, the extract was analysed by GC-MSⁿ. Benzophenone-d₁₀ was used as internal standard. The presented method is validated in terms of linearity, recovery, repeatability and intra-laboratory reproducibility, specificity, limit of detection and limit of quantification. In conclusion, this method is able to detect both BP and 4MBP at very low concentrations (LOD = 2 μg kg⁻¹) in breakfast cereals.