On the other hand, aspirin was not found in three of the 42 samples. Figure shows that for the measurement from May 2020 indeed no signal was found around 1.67 minutes for the precursor mass of aspirin. To complement the suspect screening, a full identification workflow using feature detection and componentization was also performed. It is known that depending on the workflow used different compounds can be detected. Hence, the use of both suspect screening and identification workflows can complement each other. Using the sample from April 2019, the identification entry for aspirin was evaluated (Figure ). It can be seen that the same precursor peak was detected but no fragments were matched with the library entry. Looking at the component, the fragment of 167.004 Da was componentized to the aspirin precursor ion.