Variables: pH electric_conductivity Keywords: monitoring Substances: 1-Naphthylacetic acid (PRPINYUDVPFIRX-UHFFFAOYSA-N) 1-Propanesulfonate (KCXFHTAICRTXLI-UHFFFAOYSA-N) 3-5-Diiodo-L-tyrosine (NYPYHUZRZVSYKL-ZETCQYMHSA-N)