Variables: pH Keywords: MetFrag monitoring Substances: 18-beta-Glycyrrhetinic acid (MPDGHEJMBKOTSU-YKLVYJNSSA-N) 1-Hydroxy-Benzotriazole (ASOKPJOREAFHNY-UHFFFAOYSA-N) 1-Naphthylacetic acid (PRPINYUDVPFIRX-UHFFFAOYSA-N) 2-amino-4-6-dimethoxypyrimidine (LVFRCHIUUKWBLR-UHFFFAOYSA-N)