Optimization of the matrix solid phase dispersion extraction procedure for the analysis of polybrominated diphenyl ethers in human placenta

Characterization of prenatal exposure to hazardous chemicals most often relies upon the analysis of cord blood. However, human placenta is an appropriate tissue alternative with noteworthy advantages. Owing to analytical challenges, reports on placental levels of toxic chemicals are limited. The purpose of this study was to establish a reliable, cost-effective, and relatively fast and simple method to extract polybrominated diphenyl ethers (PBDEs) from human placenta for analysis using gas chromatography coupled with mass spectrometry (GC/MS). The matrix solid phase dispersion (MSPD) method was optimized for the extraction and analysis of 43 PBDEs (including BDE209) from human placenta samples. Different sorbents, sample conditions, grinding methods, elution solvents, and single and repeated extractions were compared for their effects on the extraction efficiency. The performance of the optimized method was validated by analyzing spiked placenta samples and a standard reference material of fish tissue. Congener specific PBDE recovery ranged from 91% to 114% for the spiked samples and 89% to 115% for a standard reference material (SRM) of fish tissue. The optimized MSPD procedure was compared with two conventional extraction methods. The extraction efficiency of MSPD was found to be comparable with that of the traditional Soxhlet method and superior to that using a liquid extraction method. Twenty two PBDEs were detected in all of the five samples collected in Chicago in 2008. This is the first description of PBDEs detected in human placentas in the U.S.