This study presents the development and validation of a new analytical method for the simultaneous determination of fifteen analytes classified as halogenated
flame retardants (
HFRs) - nine
brominated diphenyl ethers (BDEs) and six novel
HFRs - in different kinds of mollusks using matrix solid-phase dispersion (MSPD) followed by gas chromatography coupled to negative chemical ionization-mass spectrometry (GC-NCI-MS). The proposed method is the first one developed for such a broad range of
HFRs in aquatic biota, featuring several advantages, including low
solvent and sample intake, simplicity of operation, reduced cost and integration of extraction and clean-up into a single step. Under optimal conditions, 0.5g of freeze-dried sample, 0.5g of a primary-secondary
amine (PSA) as solid support, a sorbent combination of 1.75g of
florisil (deactivated with 5% Milli-Q water), 1.75g of acidified
silica (10% (w/w) H2SO4) and 0.5g of
silica, and 10mL
dichloromethane as elution
solvent were used. Standard addition over the extract was required however for the correct quantification due to matrix effects in the GC system, particularly for novel
HFRs, that could not be compensated with the internal standards. The method afforded LODs in the range of 0.003-0.07ngg(-1) dry weight (0.0006-0.014ngg(-1) on a wet weight basis, assuming an 80% sample water content), except for
decabromodiphenyl ethane (DBDPE) (0.6ngg(-1) dry weight, 0.12ngg(-1) wet weight). The accuracy of the method was evaluated with three different types of spiked mollusk species using surrogate standards and standard addition over the extract for quantification and the recoveries were in the 70-120% range, except for bis(2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate (DEHTBP) in clam (Ruditapes philippinarum) samples (46% recovery). Moreover, the method was successfully validated with standard reference materials (SRMs) of salmon and mussel tissues for BDEs. Finally, the method was applied to the determination of
HFRs in different kind of freeze-dried mollusks: mussel (Mytilus galloprovincialis), cockle (Cerastoderma edule) and clam (R. philippinarum). Raft cultured mussels showed the highest concentrations of
HFRs (up to 0.8ngg(-1) wet weight of BDE-209).