"Concentration of 2,3,3',4,4',5,5'-heptachlorobiphenyl {PCB189 CAS 39635-31-9} per unit volume of the water body [dissolved plus reactive particulate phase]"@en . . "SDN:P01::SCES0049" . "Amount (mass or number of moles) of the analyte per unit volume of an unfiltered sample of any fresh or salt water body."@en . .