Gas chromatography-electrostatic field Orbitrap high resolution mass spectrometry for screening 70 organic pollutants in infant cereal-based supplementary foods

This study established a method using gas chromatography-electrostatic field Orbitrap high-resolution mass spectrometry (Orbitrap GC-MS) for the simultaneous determination of 70 organic pollutants across 4 categories: organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and phthalates (PAEs) in infant cereal-based supplementary foods. Techniques integrating cryogenic centrifugation and lipid and protein adsorbent (LPAS) purification were employed. The precise mass numbers of target compounds were determined by Orbitrap GC-MS in full-scan mode (Full MS), which effectively minimized matrix interferences in these foods. Method validation on rice flour samples demonstrated that the 70 compounds exhibited excellent linearity within their respective mass concentration ranges, with correlation coefficients all exceeding 0.995. The detection limits for this method ranged 0.10–1.00 μg/kg, while the quantification limits varied 0.3–3.0 μg/kg, meeting the established detection requirements. The average spike recovery of the 70 compounds at 3 spiked levels (5, 20, and 100 μg/kg) ranged 75.3%–119.3%, with relative standard deviations ranging 1.8%–10.8%. Both inter-day and intra-day precision demonstrated relative standard deviation values below 15%. This method was applied to analyze 100 samples of commercial infant cereal-based supplementary food, revealing the presence of PAEs and PAHs in 12.0% of the samples. Notably, no OCPs or PCBs were detected. The detected concentrations of benzo[a]pyrene (BaP) and dibutyl phthalate (DBP) were (4.2 ± 0.1) and (1.8 ± 0.3) μg/kg, respectively. This method is straightforward, highly sensitive, and suitable for the rapid screening and confirmation of 70 organic pollutants in infant cereal-based supplementary foods.