Colorimetric determination of urea using diacetyl monoxime with strong acids
Fig 4
Changes in nitrogen form over time.
Concentrations of nitrogen in urea and ammonium over 30 days in recirculating columns (n = 2) controlled at pH 7 with sulfuric acid addition. Total N represents the sum of N from urea and ammonium. Error bars represent standard error, n = 2.