"Uptake rate standard deviation of nitrate {NO3- CAS 14797-55-8} per hour per unit volume of the water body [particulate >GF/F phase] by isotope-labelled tracer addition, incubation at unspecified light level, cascade filtration and mass spectrometry on residue and summation of size-fractionated values"@en . . "NTSDIIP6" . "Measurements made by isotope-doped incubation experiment followed by counting particulates collected on each filter of a filter cascade down to a GF/F filter. Value obtained by summing the size-fractionated data." . .