[Determination of 19 kinds of phthalic acid esters in pre-prepared dishes by gas chromatography-mass spectrometry].

Abstract

To develop and validate a gas chromatography-mass spectrometry(GC-MS) method for the simultaneous determination of 19 phthalic acid esters(PAEs), including o-, m-, and p-di(2-ethylhexyl) terephthalate, in commercially available prepared dishes, with a focus on meat and aquatic product-based categories. In accordance with China's national standard GB 5009.271-2016 Food Safety National Standard-Determination of Phthalate Esters in Foods, homogenized samples were extracted with hexane, purified using a Silica/PSA solid-phase extraction column, and separated via a capillary chromatographic column. Analysis was performed by GC-MS in selected ion monitoring(SIM) mode, with quantification achieved through the internal standard method. Market samples of meat-and aquatic product-based prepared dishes were tested. The method demonstrated excellent linearity for 19 plasticizing agent within concentration ranges of 0.02-1.00 mg/kg(0.50-10.00 mg/kg for diisononyl phthalate(DINP)), with correlation coefficients(r) ≥ 0.993. At spiked levels of 0.1, 0.3 and 1.0 mg/kg, mean recoveries ranged from 78.0% to 119.4%, with relative standard deviations(RSDs) of 0.5%-11.8%(n=6). Detection frequencies for di(2-ethyl) hexyl phthalate, diisobutyl phthalate, dibutyl phthalate and di(2-ethyl) hexyl terephthalate reached 100%, 94.7%, 94.7%, and 78.9%, respectively, while the remaining 15 PAEs were below the limit of detection(LOD). Concentration ranges for detectable plasticizing agent were 0.10-2.60 mg/kg(di(2-ethyl) hexyl phthalate), not detected(ND)-0.38 mg/kg(diisobutyl phthalate), ND-0.35 mg/kg(dibutyl phthalate), and ND-0.40 mg/kg(di(2-ethyl) hexyl terephthalate). The optimized GC-MS method exhibits high applicability for the simultaneous quantification of 19 PAEs in prepared dishes.