One or more known compounds of a sample are ionized. At least one precursor ion corresponding to a compound of the one or more known compounds is selected and fragmented, producing a product ion mass spectrum for the precursor ion. An m/z tolerance probability function that varies from 1 to 0 with increasing values of an m/z difference between two mass peaks and that includes one or more values between 1 and 0 is received. A library product ion mass spectrum for the at least one compound is retrieved from a memory. An m/z difference between at least one experimental product ion mass peak in the product ion mass spectrum and at least one library product ion mass peak in the library product ion mass spectrum is calculated. An m/z tolerance probability that determines if the two peaks are corresponding peaks is calculated from the m/z difference using the probability function.
展开▼