Keywords: monitoring Substances: 5-Fluorouracil (GHASVSINZRGABV-UHFFFAOYSA-N) 1-(3-Chlorophenyl)-piperazin (VHFVKMTVMIZMIK-UHFFFAOYSA-N) 1-(3-Trifluoromethylphenyl)-piperazine (KKIMDKMETPPURN-UHFFFAOYSA-N) 5-Hydroxy Diclofenac (VNQURRWYKFZKJZ-UHFFFAOYSA-N)