Concentration of ammonium {NH4+ CAS 14798-03-9} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis NH4_Unfilt_Col Amount (mass or number of moles) of the analyte per unit volume of an unfiltered sample of any fresh or salt water body determined by an operational method that converts the analyte to a coloured substance and determines the strength of that colour. 2015-07-08 11:09:34.0 SDN:P01::AMONAATX SDN:P01::AMONAATX SDN:P01::AMONAATX 4 4 2015-07-08 11:09:34.0 accepted false