Determination of nine hydroxylated polybrominated diphenyl ethers in water by precolumn derivatization-gas chromatography–mass spectrometry

• The assay of OH-PBDEs in water has always been a challenging problem.
• N,O-bis (trimethylsilyl) trifluoroacetamide was used as derivatization reagent.
• A new, simple and sensitive method for simultaneous determination of nine OH-PBDEs in water was established.
• The method could be applied to four different kinds of environmental water.

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs), acting as emerging endocrine disruptors, have aroused more and more concern recently. Produced from natural source or metabolism of PBDEs, OH-PBDEs are more toxic than their parent compounds. However, few analytical methods are available for sensitive determination of these compounds especially in water. In this study, a method of determination of nine OH-PBDEs in lake, reservoir, river and sewage treatment plant effluent was established using N,O-bis (trimethylsilyl) trifluoroacetamide (BSTFA) as derivatization reagent combined with gas chromatography–mass spectrometry (GC–MS). Optimal extraction solvent and derivatization factors such as the amount of BSTFA, time, temperature and dissolution solvent were determined experimentally. After extracted by hexane–dichloromethane (1:1, v/v), extracts were evaporated to almost dry, then BSTFA was added to the residue and heated at 90 °C for 30 min. The remains were dried under a stream of nitrogen and redissolved in hexane. The solution was separated in DB-35MS column, then determined by GC–MS in selected ion mode and full scan monitoring mode, and quantified by external standard method. The working curves were obtained using sample matrix in order to eliminate the matrix interference. Linear range was from 0.02 μg L−1 to 30 μg L−1. Limits of detection and quantification ranged from 0.0039 μg L−1 to 0.0220 μg L−1 and 0.0130 μg L−1 to 0.0733 μg L−1, respectively. Two different spiked levels were measured with 5 parallel tests for each level. The results indicated that the relative standard deviations were less than 14.08%. The method has been applied to lake water, reservoir water, river water and sewage treatment plant effluent. Five OH-PBDEs including 2′-OH-BDE3, 3′-OH-BDE7, 2′-OH-BDE28, 4′-OH-BDE17 and 5′-OH-BDE99 were detected in all the samples collected in Baoding, China. This method is simple, high sensitive, and suitable for simultaneous determination of nine OH-PBDEs in different environmental water.