Variables: total_organic_carbon Systems: groundwater Substances: 18-beta-Glycyrrhetinic acid (MPDGHEJMBKOTSU-YKLVYJNSSA-N) 2-amino-4-6-dimethoxypyrimidine (LVFRCHIUUKWBLR-UHFFFAOYSA-N) 1-(3-Trifluoromethylphenyl)-piperazine (KKIMDKMETPPURN-UHFFFAOYSA-N)