Development of an analytical method for the determination of polybrominated diphenyl ethers in mussels and fish by gas chromatography-Inductively coupled plasma mass spectrometry

Six congeners of polybrominated diphenyl ethers (PBDEs): BDE 28, BDE 47, BDE 99, BDE 100, BDE 153 and BDE 154, were determined by a reliable and sensitive analytical method based on gas chromatography coupled to inductively coupled plasma mass spectrometry (GC-ICP-MS) in mussel and fish tissue samples. For their extraction, 30 min of ultrasound-assisted extraction with a 25% aqueous solution of tetramethylammonium hydroxide (TMAH) and an additional 2 h of mechanical shaking with tris(hydroxymethyl)aminomethane (Tris)-citrate buffer and iso-octane were applied. An effective cleaning, with minor solvent consumption, was achieved by passing the extract through a column filled with Florisil. PBDEs in the organic phase were quantified by GC-ICP-MS. Accuracy checks were performed by analyzing reference materials NIST SRM 2974a (freeze-dried mussel tissue) and SRM 1946 (fresh fish tissue homogenate) samples with a standard addition calibration method and by comparative analysis with species-specific isotope-dilution GC-ICP-MS. Good agreement of results between the determined and certified values were obtained (recoveries lied between 94 and 105%). Limits of detection (LODs) expressed on wet weight (ww) basis were 0.003 ng g−1 for BDE 28, 0.006 ng g−1 for BDE 47, 0.008 ng g−1 for BDE 99, 0.004 ng g−1 for BDE100, 0.005 ng g−1 for BDE 153 and 0.009 ng g−1 for BDE 154. The analytical method was applied for the determination of PBDEs in marine mussels and fish samples from the northern Adriatic Sea and fish samples from the Sava River. Among the six PBDEs congeners determined, BDE 47, BDE 100 and BDE 99 were commonly detected in the samples analysed.