Variables: electric_conductivity concentration Keywords: high resolution mass spectrometry land use Substances: Adenosine (OIRDTQYFTABQOQ-UHFFFAOYSA-N) 1-3-Dimethyl-2-imidazolidinon (CYSGHNMQYZDMIA-UHFFFAOYSA-N) 1-Hydroxy-Benzotriazole (ASOKPJOREAFHNY-UHFFFAOYSA-N)