Determination of 11 photoinitiators and their migration into tea and milk by gas chromatography-tandem mass spectrometry (MSPD-GC-MS/MS)

Abstract

Based on the use of multi-walled carbon nanotubes (MWCNTs) in matrix solid-phase dispersion (MSPD) extraction, a novel, rapid and reliable method was developed for the analysis of 11 photoinitiators used in food packaging ink followed by quantitation by gas chromatography-tandem mass spectrometry. The use of MWCNTs was compared with that of the adsorbents C18 silica and diatomaceous earth (DE) in the MSPD procedure. The extracts obtained using MWCNTs were better than those obtained using C18 and DE. Using the newly developed method, recoveries ranged from 70.9% to 121.4%, the RSDs were between 0.1% and 3.5%, and the LOQs ranged from 0.002–0.008 mg kg⁻¹. This method was used to test the degree of migration of the photoinitiators into food, showing that the migration into tea powder increased with increasing initial concentration of the pollutants, while this phenomenon was not found in milk powder. The ability of the photoinitiators to migrate into food matrices was shown to be closely related to their molecular weight and to their molecular conformation, as well as the particular characteristics of the food matrix.