Variables: dissolved_organic_carbon total_organic_carbon electric_conductivity Substances: 18-beta-Glycyrrhetinic acid (MPDGHEJMBKOTSU-YKLVYJNSSA-N) 1-(3-Trifluoromethylphenyl)-piperazine (KKIMDKMETPPURN-UHFFFAOYSA-N) 4-Hydroxy-1-(2-hydroxyethyl)-2-2-6-6-tetramethylpiperidine (STEYNUVPFMIUOY-UHFFFAOYSA-N)