Variables: dissolved_oygen electric_conductivity Keywords: high resolution mass spectrometry Substances: 1-Naphthylacetic acid (PRPINYUDVPFIRX-UHFFFAOYSA-N) 1-(3-Trifluoromethylphenyl)-piperazine (KKIMDKMETPPURN-UHFFFAOYSA-N) 2 -2 -Difluorodeoxyuridin (FIRDBEQIJQERSE-QPPQHZFASA-N)