[Simultaneous determination of 14 phthalate ester residues in animal innards by gas chromatography-mass spectrometry with electron impact ionization].

An analytical multiresidue method was developed for the simultaneous determination of 14 phthalate esters (PAEs) in animal innards by gas chromatography-mass spectrometry with electron impact ionization (GC-EI/MS). After the optimization of different parameters such as the extraction solvent, PAEs were extracted from animal innards with hexane-dichloromethane (1:1, v/v) in an ultrasonic bath and cleaned up on a Florisil column, then were determined by GC-EI/MS in selected ion monitoring mode with diphenyl phthalate (DPhP) as internal standard. The recovery studies were performed at 100, 200 and 400 microg/kg levels for each PAE, and the recoveries ranged from 60% - 110% with the relative standard deviations between 0.8% and 10.3% for different PAEs. The detection limit of the method was less than 1.74 microg/kg for most of PAEs except dimethoxyethyl phthalate (DMEP) and di(2-ethoxyethyl) phthalate (DEEP). The method was linear over the range of 50.0 - 800.0 microg/kg with the correlation coefficients larger than 0.999 4. The method has been successfully, applied to the determination of 14 PAEs in six animal innards.