Variables: total_organic_carbon concentration Substances: 5-Fluoro Cytosine (XRECTZIEBJDKEO-UHFFFAOYSA-N) 1-Propanesulfonate (KCXFHTAICRTXLI-UHFFFAOYSA-N) 3-5-dibromo-4-hydroxybenzoic acid (PHWAJJWKNLWZGJ-UHFFFAOYSA-N) 3-5-Diamino-2-4-6-triiodobenzoic acid (GOQCZMZLABPEME-UHFFFAOYSA-N)