Residue Analysis and Exposure Assessment of Methylsiloxane Oligomers in Fried Chicken and French Fries

The fried food in fast food is deeply loved by consumers. However, with the increasing concern about the safety of volatile methylsiloxanes, the residue of oligomer monomer of methylsiloxanes from defoamer PDMS in fried food needs to be studied urgently. In this study, an efficient and sensitive method for the determination of methylsiloxane oligomers in fried chicken and French fries was established using QuEChERS-gas chromatography-tandem mass spectrometry (GC-MS/MS). A total of 33 fried chickens and 30 French fries purchased from fast food restaurants were analyzed and a preliminary exposure assessment using a point assessment method was carried out. The results showed that octamethyl cyclotetrasiloxane (D4)~hexamethyldisiloxane (D18) and decamethyl tetrasiloxane (L4)~triaconta methyltetradecasiloxane (L14) were detected, and the median total content of methylsiloxane oligomers in fried chicken (514.61 ng·g⁻¹) was higher than that in French fries (83.4 ng·g⁻¹). The estimated daily intake (EDI) of methylsiloxanes (molecular weight <1000) in fried chicken and French fries was 164.94 ng·kg⁻¹·d⁻¹ and 13.09 ng·kg⁻¹·d⁻¹, respectively, which was lower than the PDMS acceptable daily intake (ADI) (0.8 mg·kg⁻¹·d⁻¹). However, the potential hazards of some volatile methylsiloxanes such as D4~dodecamethyl cyclohexasiloxane (D6) need to be further investigated after long-term low dose intake and enrichment. This study provides a scientific basis for the safety evaluation and subsequent in-depth study of methylsiloxanes residues in fried food fast food.