A novel biomass-derived sorbent trap was developed for HgT(g) monitoring. The trap was based on rice husk char and impregnated with bromine (RHC-HBr). The RHC-HBr trap was comparable with commercial AC trap for HgT(g) monitoring. High accuracy field sampling by the RHC-HBr trap was confirmed by QA/QC. The RHC-HBr trap was used to report Hg migration through existing APCDs.