Substances: 4-Formylaminoantipyrin (4-FAA) (WSJBSKRPKADYRQ-UHFFFAOYSA-N) 5-Fluoro Cytosine (XRECTZIEBJDKEO-UHFFFAOYSA-N) 5-Hydroxy Diclofenac (VNQURRWYKFZKJZ-UHFFFAOYSA-N) Keywords: high resolution mass spectrometry