Determination of the binding of polybrominated biphenyls to serum proteins by negative chemical ionization mass spectrometry

Negative chemical ionization mass spectrometry was used to quantify polybrominated biphenyl (PBB) congeners in protein fractions obtained by immunoprecipitation from the sera of Michigan subjects. Of the 80% PBB bound to protein, 73% was bound to apolipoprotein B and the rest to apolipoprotein A. The non-protein-bound PBB (20%) was directly extractable and is probably associated with lipids. There was no evidence of differential binding of PBB congeners to any of the serum fractions.