Concentration of three types of nitrogen in human urine.

Liquid chromatographic determination of ammonium in water

“…The most tedious operation in radiostrontium determination is concentrating it from urine and separating the radionuclide from the mixture of other radionuclides. The methods of precipitation (1-4), ion exchange (5-7), and extraction (8)(9)(10)(11) are frequently used for this purpose. Extraction procedures are especially advantageous due to their speed and high selectivity.…”

“…Ammonium is currently determined by the ammonia electrode method (1)(2)(3)(4), by the molecular absorption method (5, 6), and by the ion chromatographic method (7)(8)(9)(10). It is also determined by phenate or titration method after distillation to remove interfering substances in water (11).…”