"Concentration of 2,3',4,4',5,5'-hexachlorobiphenyl {PCB167 CAS 52663-72-6} per unit volume of the water body [dissolved plus reactive particulate phase]"@en . . "SDN:P01::SCES0041" . "Amount (mass or number of moles) of the analyte per unit volume of an unfiltered sample of any fresh or salt water body."@en . .