Determination of Polybrominated Diphenyl Ethers and Hydroxylated Analogues in Serum Using High Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry with Online Solid Phase Extraction

Online solid phase extraction-high performance liquid chromatography-inductively coupled plasma mass spectrometry (Online SPE-HPLC-ICP-MS) technique was developed for simultaneous determination of 6 kinds of polybrominated diphenyl ethers and 5 kinds of hydroxyl metabolites in serum. A serum sample (200 μL) was directly analyzed after protein precipitation and dilution. The target analytes were automatically enriched on a solid phase extraction column, and then separated and analyzed by liquid chromatography-inductively coupled plasma mass spectrometry with methanol/acetonitrile/water as mobile phase. The main parameters such as loading rate, elution time and elution solvent were optimized. As a result, Oasis HLB was selected as the SPE column, the loading solvent was pure water at a rate of 3.0 mL/min, the elution solvent was methanol-acetonitrile-water (54:26:20, V/V), the elution flow rate was 1.0 mL/min, and the liquid chromatography column was ZORBAX Eclipse Plus C18. The limits of quantification (LOQ) of the method were 0.14–0.74 ng/L, the recoveries were 61.8%–77.7%, and the relative standard deviations (RSDs) of the results were 3.7%–10.1% (n = 3). The established method was successfully applied to the analysis of 30 serum samples. A total of 4 kinds of polybrominated diphenyl ethers and 2 kinds of hydroxy polybrominated diphenyl ethers were detected, and their occurrence characteristics were consistent with previous reports. The results showed that this method could be applied to analyze actual samples in large quantities, which was of great practical value.