1. A mass spectrometry system, comprising: (a) an ion source to ionize a sample stream; (b) a detector positioned downstream with respect to the ion source to acquire mass spectrometry data of the sample stream; and (c) a data analyzer connected to the detector and comprising: (i) a chromatogram generator to process the mass spectrometry data to derive a chromatogram; (ii) a data point selector to apply a selection criterion to the chromatogram to select data points from the chromatogram; and (iii) a peak discriminator to apply a discriminating criterion to the data points to detect a peak in the chromatogram, wherein the peak is indicative of a presence of an analyte in the sample stream.