Abstract: A method for ranking analytes includes the steps of analyzing an experimental analyte in a mass spectrometer. The method includes comparing the experimental analyte to a plurality of candidate analytes in a library hit list, and assigning a cumulative confidence score to each candidate analyte based on the steps of comparing the experimental analyte to the candidate analytes based on a library similarity score, comparing the experimental analyte to the candidate analytes based on of a presence of the most abundant isotope of a molecular ion and its mass, comparing the experimental analyte to the candidate analytes based on an abundance of fragment ions and a mass of the fragment ions, and, in some implementations, comparing the experimental analyte to the candidate analytes based on a retention index value. The method includes ranking the candidate analytes based on the cumulative confidence score of each candidate analyte.