Variables: total_organic_carbon Keywords: high resolution mass spectrometry Substances: 5-Fluorouracil (GHASVSINZRGABV-UHFFFAOYSA-N) 5-Fluoro Cytosine (XRECTZIEBJDKEO-UHFFFAOYSA-N) 1-(3-Trifluoromethylphenyl)-piperazine (KKIMDKMETPPURN-UHFFFAOYSA-N)