Determination of 9 Phthalic Acid Esters in Road Dust by Gas Chromatography-Mass Spectrometry with Matrix Solid Phase Dispersion Assisted Accelerated Solvent Extraction

The composition of road dust samples was complex and there was no corresponding standard detection method. Based on this fact, a method mentioned by the title was proposed by combining accelerated solvent extraction (ASE) with matrix solid phase dispersion (MSPD). The road dust sample (10.0 g) was mixed well with 10.0 g of floritic silica, then put into the extraction tank (pre-adding a layer of diatomaceous earth with a thickness of about 0.5 cm), and extracted twice with a mixture of n-hexane-dichloromethane at a volume ratio of 1∶1 at 100 ℃. The extract was concentrated to about 5.0 mL, and then blown to about 1.0 mL by nitrogen. Its volume was made up to 1.0 mL with n-hexane, in which 9 phthalic acid esters (PAEs), including dimethyl phthalate (DMP), diethyl phthalate (DEP), dipropyl phthalate (DPRP), diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), dicyclohexyl phthalate (DCHP), phthalate (2-ethylhexyl) ester (DEHP), and n-octyl phthalate (DNOP), were determined by gas chromatography-mass spectrometry. As shown by the results, the linear range of the standard curves of 9 PAEs was 0.1-5.0 mg·L^-1, with detection limits (3.143s) in the range of 1.10-1.39 μg·kg^-1. Test for recovery was made by the standard addition method, giving results in the range of 76.6%-107%, with RSDs(n=6) of the determined values less than 10%. This method was applied to analysis of the actual samples, with higher detection amounts of 8.06-233 μg·kg^-1 for DIBP, 23.9-3 148 μg·kg^-1 for DBP, and 16.5-4 106 μg·kg^-1 for DEHP, respectively.