Simultaneous determination of selected estrogenic endocrine disrupting chemicals and bisphenol A residues in whole milk using fabric phase sorptive extraction coupled to HPLC-UV detection and LC-MS/MS

A simple and sensitive analytical methodology is developed for rapid screening and quantification of selected estrogenic endocrine disrupting chemicals and bisphenol A from intact milk using fabric phase sorptive extraction in combination with high-performance liquid chromatography coupled to ultraviolet detection/tandem mass spectrometry. The new approach eliminates protein precipitation and defatting step from the sample preparation workflow. In addition, the error prone and time-consuming solvent evaporation and sample reconstitution step used as the sample post-treatment has been eliminated. Parameters with most significant impact on the extraction efficiency of fabric phase sorptive extraction including sorbent chemistry, sample volume, extraction time have been thoroughly studied and optimized. Separation of the selected estrogenic endocrine disrupting chemicals including α-estradiol, hexestrol, estrone, 17α-ethinyl estradiol, diethylstilboestrol, and bisphenol A were achieved using a Zorbax Extend-C18 high-performance liquid chromatography column (15 cm × 4.6 mm, 5 μm particle size). The limit of detection values obtained in fabric phase sorptive extraction with high-performance liquid chromatography with ultraviolet detection ranged from 25.0 to 50.0 ng/mL. The method repeatability values were 3.6-13.9 (relative standard deviation, %) and intermediate precision values were 4.6-12.7 (relative standard deviation, %). The fabric phase sorptive extraction method was also coupled to liquid chromatography with tandem mass spectrometry for identifying each endocrine disrupting chemical at 10 ng/mL.