Variables: dissolved_oygen electric_conductivity pH Substances: 18-beta-Glycyrrhetinic acid (MPDGHEJMBKOTSU-YKLVYJNSSA-N) 1-[(4-Chlorophenyl)phenylmethyl]piperazine (UZKBSZSTDQSMDR UHFFFAOYSA-N) Systems: groundwater Keywords: monitoring high resolution mass spectrometry land use