Moreover, pH, Total Phosphorus (TP), Total Nitrogen (TN), Dissolved Reactive Phosphorus (DRP), Oxidized Nitrogen (NOx−), Colored Dissolved Organic Matter (CDOM), and Conductivity (COND) were measured in the laboratory [24]. Smith and McBride [24] and Davies-Colley et al. [34] ...
appearance of the pink color in the soil solution samples at 470 nm, through the diazotization reaction between the nitrites in the samples with certain aromatic amines, in which a diazonium salt is formed that can then be coupled with another amine or phenol to form an intensely colored ...