Variables: total_organic_carbon concentration Systems: groundwater Substances: 1-[(4-Chlorophenyl)phenylmethyl]piperazine (UZKBSZSTDQSMDR UHFFFAOYSA-N) 18-beta-Glycyrrhetinic acid (MPDGHEJMBKOTSU-YKLVYJNSSA-N) 1-(3-Chlorophenyl)-piperazin (VHFVKMTVMIZMIK-UHFFFAOYSA-N)