Variables: total_organic_carbon concentration pH Keywords: high resolution mass spectrometry Substances: 1-Propanesulfonate (KCXFHTAICRTXLI-UHFFFAOYSA-N) 1-Naphthylacetic acid (PRPINYUDVPFIRX-UHFFFAOYSA-N) 2-4-D (OVSKIKFHRZPJSS-UHFFFAOYSA-N)