Variables: dissolved_organic_carbon Substances: 5-Fluorouracil (GHASVSINZRGABV-UHFFFAOYSA-N) 5-Fluoro Cytosine (XRECTZIEBJDKEO-UHFFFAOYSA-N) 4-Dimethylaminoantipyrin (Aminopyrin) (RMMXTBMQSGEXHJ-UHFFFAOYSA-N) 1-3-Dimethyl-2-imidazolidinon (CYSGHNMQYZDMIA-UHFFFAOYSA-N)