[Determination of phthalate esters in sediment by accelerated solvent extraction and gas chromatography-triple quadrupole mass spectrometry]

A method for the determination of seventeen phthalate esters in sediment by accelerated solvent extraction (ASE), gel-permeation chromatography (GPC) and gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) has been developed. The target compounds were extracted at 100 degrees C and 103.4 MPa (1500 psi) by ASE using the mixtures of dichloromethane and acetone (1:1, v/v) as solvent. In order to eliminate the interferences from larger molecular sizes, the extract was purified at a flow rate of 5.0 mL/min by GPC. Following that, the extract was concentrated to a final volume of 1 mL exactly. The GC-MS/MS was applied to quantitative and qualitative analysis. Internal standard calibration approach was adopted, and the detection limits of seventeen phthalate esters ranging from 0.05 to 0.40 microg/kg were obtained. The correlation coefficients were beyond 0.996, the recoveries were from 50.5% to 107.9%, and the relative standard deviations were from 3.5% to 13.9%. Besides, the surrogate compounds spiked were used to monitor the performance of the method, and the recoveries were from 65.3% to 95.8% for the three surrogate compounds. The method is fast, sensitive and exact for analyzing seventeen phthalate esters simultaneously.