Keywords: monitoring Substances: 1-Methyl-Benzotriazole (HXQHRUJXQJEGER-UHFFFAOYSA-N) 4-Acetamidoantipyrin ( N-Acetyl-4-Aminoantipyrin 4-AAA) (OIAGWXKSCXPNNZ-UHFFFAOYSA-N) 5-Chloro-2-methyl-4-isothiazolin-3-on (CMI) (DHNRXBZYEKSXIM-UHFFFAOYSA-N) 2 -2 -Difluorodeoxyuridin (FIRDBEQIJQERSE-QPPQHZFASA-N)