Variables: pH concentration Substances: 2 -2 -Difluorodeoxyuridin (FIRDBEQIJQERSE-QPPQHZFASA-N) 1-[(4-Chlorophenyl)phenylmethyl]piperazine (UZKBSZSTDQSMDR UHFFFAOYSA-N) 1-Hydroxy-Benzotriazole (ASOKPJOREAFHNY-UHFFFAOYSA-N)