Residues in Drinks by High Performance Liquid Chromatography-Tandem Mass Spectrometry

A high performance liquid chromatography-tandem mass spectrometric (HPLC-MS/MS) method was established for the determination of residues of phthatate esters (PAEs), including di(2-ethylhexyl) phthalate (DEHP) and diisononyl phthalate (DINP) in drinks.2.0 g drink was shaken and extracted with 8 mL methanol.The extract was added to 10mL methanol and centrifuged. The supermatant was filtered by filter membrane. Then the DEHP and DINP were identified in multiple reactions monitoring (MRM) mode by the mass spectrometry with electrospray in positive ionization mode. The linear range for DEHP was 2-200 mu g/L and DINP was 10-1000 mu g/L, with the correlation coefficients (r(2)) more than 0.998. No significant matrix effect was found for spiked samples. The recoveries of DEHP and DINP spiked in drinks were 86.2%-111.6% at spiked levels of 0.01-5 mg/kg. The relative standard deviations (RSDs) were less than 11.0%. The limits of quantization (LOQs) were 0.01 mg/kg for DEHP, 0.05 mg/kg for DINP. The proposed procedure was applied to the analysis of 63 real samples from Xiamen,Fujian province (China), of which 34 positive samples were found. This method was sensitive and accurate for the determination of DEHP and DINP in drinks.