Variables: total_organic_carbon electric_conductivity Substances: 18-beta-Glycyrrhetinic acid (MPDGHEJMBKOTSU-YKLVYJNSSA-N) 3-5-6-Trichloro-2-pyridinol (WCYYAQFQZQEUEN-UHFFFAOYSA-N) 1-[(4-Chlorophenyl)phenylmethyl]piperazine (UZKBSZSTDQSMDR UHFFFAOYSA-N) 1-Naphthylacetic acid (PRPINYUDVPFIRX-UHFFFAOYSA-N) 2 -2 -Difluorodeoxyuridin (FIRDBEQIJQERSE-QPPQHZFASA-N) Systems: groundwater Keywords: monitoring high resolution mass spectrometry land use