Detection of 20 phthalate esters in breast milk by GC-MS/MS using QuEChERS extraction method.

A detection method for 20 different phthalate esters (PAEs) in breast milk analyzed by quick, easy, cheap, effective, rugged, and safe (QuEChERS) clean-up with five internal standards and quantitative GC-MS/MS was established. This method can effectively remove interfering substances such as lipids and fatty acids from breast milk using acetonitrile as the extraction solvent and PSA/C18 as clean-up materials. The 20 PAEs had a linear range of 5.0-500.0 µg/L and recoveries of 83.3-123.3% with RSDs of 0.2-7.6% (n = 6). The method detection limits (LODs) were 0.004-1.3 µg/kg. Dimethyl phthalate (DMP), Diethyl phthalate (DEP), Diisobutyl phthalate (DIBP), Di-n-butyl phthalate (DBP) and bis(2-ethylhexyl) phthalate (DEHP) were detected in the 35 breast milk samples, with median levels of 1.2, 6.8, 7.3, 32.9 and 13.6 μg/kg, respectively, and the concentrations of 20 PAEs ranged between 0.5 and 137.3 μg/kg. This is a fast, simple, sensitive and accurate method for the detection of 20 PAEs in breast milk or dairy products.