In one aspect, a method of performing mass spectrometric analysis of a sample, e.g. a food-based sample, is disclosed, which comprises ionizing the sample to generate a plurality of ions, introducing the plurality of ions into a mass filter configured to provide a high m/z cutoff greater than a maximum m/z ratio of ions associated with one or more analytes of interest in the sample so as to allow passage of the analyte ions while inhibiting passage of ions having m/z ratios above said high m/z cutoff, and performing a mass analysis of ions passing through said mass filter. In a related aspect, a mass spectrometer is disclosed, which comprises an atmospheric pressure ion source, a first mass filter, a user interface and a controller.