Variables: total_organic_carbon Keywords: high resolution mass spectrometry land use Substances: 1-3-Dimethyl-2-imidazolidinon (CYSGHNMQYZDMIA-UHFFFAOYSA-N) 4-5-Dichloro-2-n-octyl-isothiazol-3(2H)-on (DCOIT) (PORQOHRXAJJKGK-UHFFFAOYSA-N)