Keywords: monitoring Substances: 1-Methyl-Benzotriazole (HXQHRUJXQJEGER-UHFFFAOYSA-N) 2 -3 -di-O-acetyl-5 -deoxy-5-fluorocytidin (NWJBWNIUGNXJGO-RPULLILYSA-N) Acetochlor-OXA (OTKTUNJJKYTOFF-UHFFFAOYSA-N) 2 -2 -Difluorodeoxyuridin (FIRDBEQIJQERSE-QPPQHZFASA-N)