Variables: dissolved_organic_carbon Substances: 4-Dimethylaminoantipyrin (Aminopyrin) (RMMXTBMQSGEXHJ-UHFFFAOYSA-N) 2-n-Octyl-4-isothiazolin-3-on (OIT) (JPMIIZHYYWMHDT-UHFFFAOYSA-N) 1-Methyl-Benzotriazole (HXQHRUJXQJEGER-UHFFFAOYSA-N) 5-Fluoro Cytosine (XRECTZIEBJDKEO-UHFFFAOYSA-N)