To illustrate the operation and efficacy of the algorithms described in Section 2.2, three different test cases are presented. All computations use the parameter values outlined in Table . For librarybased methods (i.e., SS-HM and iHS-HM), we used the Scientific Working Group for the Analysis of Seized Drugs (SWGDRUG) MS Library Version 3.3 as the reference library. Current versions of the SWGDRUG MS Library can be obtained at 28 Example 1: Consider the mass spectrum of an analyte shown as Figure . Using the PIM (Algorithm 1), we predicted its molecular mass to be 𝑚 " ! = 383 Da. With that prediction, there is only one questionable neutral loss estimate with an abundance greater than the minimum acceptable abundance of fragment ions, 𝜖 % , assigned a default value of 0.0% as defined in Table . The relative intensity for the questionable neutral loss estimate, however, is 0.5 % and the abundance of the proposed molecular ion is 35%. The questionable peak abundance ratio determined by ( ) is approximately 0.01 and the index 𝐼 * + " determined by ( ) is computed to be 0.96.