Single-run gas chromatography-mass spectrometry method for the analysis of phthalates, polycyclic aromatic hydrocarbons, and pesticide residues in infant formula based on dispersive microextraction techniques

Abstract

For the first time, three important contaminant groups (phthalates, polycyclic aromatic hydrocarbons, and pesticides), traditionally monitored by separated methods, were simultaneously analyzed in complex infant formula matrices. An accurate and sensitive analytical method based on gas chromatography-mass spectrometry (GC–MS) was developed for 45 food contaminants. Dispersive solid-phase extraction and low-density solvent-based dispersive liquid–liquid microextraction techniques were combined for clean-up and analyte enrichment purposes. Distinct GC–MS injection conditions were studied with the highest analytical responses obtained at high temperatures in pulsed splitless mode at high pulse pressures. Low matrix effects were observed for the majority of analytes under study, indicating a possible relation of these effects with the physicochemical parameters of the analytes. Adequate method performance characteristics were achieved, covering limits of detection and quantification sufficiently low to monitor the regulated compounds at the maximum limits fixed for infant formula. Furthermore, the greenness and practicality of the proposed method were evaluated through the AGREE and BAGI metric tools, respectively. In summary, the application of the proposed method to commercial infant formulas, with the identification and quantification of benzo[a]pyrene, benz[a]anthracene, dibutyl phthalate, di(2-ethylhexyl) phthalate, dimethyl phthalate, and diisobutyl phthalate at levels between 1.4 and 47.1 µg kg−1 in a total of 30.0 % samples, demonstrates their suitability for routine analysis as well as contributes to the first data on the co-occurrence of PAHs and phthalates in infant formula.