"Concentration of 2,4',5-trichlorobiphenyl {PCB31 CAS 16606-02-3} per unit dry weight of sediment <2000um"@en . . "SDN:P01::CB31SDBD" . "The quantity or mass of the specified analyte contained in a dried subsample of sediment that passes through a 2000 micron sieve."@en . .