Concentration of ammonium {NH4+ CAS 14798-03-9} per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration, indophenol synthesis, SPE extraction, HPLC purification and gas chromatography-mass spectrometry NH4_GF/FFilt_GCMS not supplied 2015-07-08 11:09:34.0 SDN:P01::AMONFSG1 SDN:P01::AMONFSG1 SDN:P01::AMONFSG1 3 3 2015-07-08 11:09:34.0 accepted false