Development of a matrix solid-phase dispersion method for the screening of polybrominated diphenyl ethers and polychlorinated biphenyls in biota samples using gas chromatography with electron-capture detection

A low cost method for the screening of six polybrominated diphenyl ethers (PBDEs) and seven polychlorinated biphenyls (PCBs) in biological samples containing up to 100% of fat is presented. Compounds are extracted from the sample and isolated from lipids using a matrix solid-phase dispersion (MSPD) cartridge and 20 ml of n-hexane as elution solvent. PBDEs and PCBs are fractionated on a second cartridge containing 2 g of a normal phase sorbent. The potential of neutral silica, Florisil and basic alumina to separate PBDEs and PCBs in two independent fractions has been evaluated. The best results were obtained using silica. PCBs are eluted, in a first fraction, using n-hexane. PBDEs are further recovered with n-hexane-dichloromethane. The applicability of the method for the screening of PBDEs and PCBs, in samples containing both groups of compounds, has been demonstrated using spiked, certified and real polluted samples from different biota materials. Globally, recoveries higher than 75% and quantification limits around 0.4 ng/g have been achieved using gas chromatography with electron-capture detection (GC-ECD).