Substances: 4-Hydroxy Diclofenac (KGVXVPRLBMWZLG-UHFFFAOYSA-N) 1-Propanesulfonate (KCXFHTAICRTXLI-UHFFFAOYSA-N) AMDOPH (IRTZMJWVZQYURE-UHFFFAOYSA-N) Keywords: high resolution mass spectrometry monitoring