Determination of 18 Phthalic Acid Esters Compounds in Oily Foodstuffs by Atmospheric Pressure Chemical Ionization(APCI) Liquid Chromatography Tandem Mass Spectrometry

A quick confirmative method was developed for determining 18 phthalic acid esters(PAEs) in oily foodstuffs by liquid chromatography tandem quadrupole mass spectrometry(LC-MS/MS),basing on the ministry of health announcement about 17 illegal PAEs in foodstuffs.The oil sample was extracted with acetonitrile.After mixed with water,n-hexane was selected as the solvent of liquid-liquid extraction.The extracts were concentrated to dry and methanol was used to dissolve residues.The separation was carried out on C18 column with the isocratic and gradient elution.The detection of 18 analytes was achieved in the positive atmosphere pressure chemical ionization(APCI) and multi-reaction monitoring(MRM) mode.With the optimized condition,the limits of quantification(LOQ) of the 18 PEAs analytes were 0.05-0.5 mg/kg.The overall recovery varies from 53.4% to 107.9%,and the relative standard deviations(RSD) were between 7.2% and 24.6%.Real sample including vegetable oil,shortening oil,chili sauce,bean sauce,and biscuit were determined 18 PAEs residues with this method and compared with the standard method.The results showed that the method was simple,accurate and suitable for the determination of 18 PAEs in oily foodstuffs.