Background ions peak shape

Figure 5.18. The peak shape of the background ions of m/z 28 versus resolving power R of a mass spectrometer.

In this case the survey scan was set as a full scan and the dependent scan as a product ion scan. The problem with data dependent acquisition is to determine the selection criteria. In most cases the system picks up the most abundant ion in the full scan spectrum. An inclusion list with masses of potential metabolites or exclusion list of known interferences significantly improves the procedure. In the example shown in Fig. 1.39, a procedure called dynamic background subtraction (DBS) was applied. This procedure considers chromatographic peak shapes and monitors not the most abundant signal in the spectrum but the largest increase of an ion in a spectrum. The advantage is that once a signal of a peak has... 

Williams, R.L., Childs, B., Dose, E.V., Guiochon, G, and Vigh, G, Peak shape distortions in the capillary electrophoretic separations of strong electrolytes when the background electrolyte contains two strong electrolyte co-ions. Anal. Chem., 69,1347,1997. 

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