A method for the determination of six isophthalate esters in plastic toys

including dimethyl isophthalate

diethyl isophthalate

diallyl isophthalate

bis(2-ethylhexyl) isophthalate

diphenyl isophthalate and di-n-octyl isophthalate was established by gas chromatography-mass spectrometry(GC-MS) with solid phase extraction(SPE).The samples were ultrasonically extracted with ethyl acetate

precipitated with methanol and purified with an HLB solid phase extraction column

then the analytes were separated on an HP-5MS column(30 m×250 μm×0.25 μm)

detected in selected ion monitoring mode and quantified by external standard method.Results showed that the standard curves for six isophthalate esters were linear over the concentration range of 0.1-5.0 mg/L

with correlation coefficients(r2) greater than 0.995.The detection limits of the method(S/N=3) were in the range of 0.22-0.60 mg/kg

and the spiked recoveries were between 87.3% and 116% with relative standard deviations of 1.5%-9.5%.The method is simple

rapid and sensitive

and is suitable for the determination of isophthalate esters in plastic toys.