Variables: electric_conductivity concentration Keywords: high resolution mass spectrometry Substances: 5-Fluorouracil (GHASVSINZRGABV-UHFFFAOYSA-N) 18-beta-Glycyrrhetinic acid (MPDGHEJMBKOTSU-YKLVYJNSSA-N) 1-3-Dimethyl-2-imidazolidinon (CYSGHNMQYZDMIA-UHFFFAOYSA-N)