One of the first things we observed when moving away from laboratory examples was that mixture mass spectra often contained low level noise peaks. This was especially true for low-resolution mass spectra where random matching of a peak in the library spectrum to a peak in the query spectrum is more likely. These noise peaks would occasionally inflate scoring metrics and complicate interpretation. To address this limitation, we now include a rudimentary "noise" filter that discards all peaks below a user-prescribed threshold (e.g., 1 % relative intensity) in both compared spectra (query and library) when computing scoring metrics. Finding an alternative method capable of filtering only true noise peaks is ongoing work, with one such alternative being the recently published method of mass defect filtering . Secondly, we now score spectra using peaks in the range of m/z 80 to the five mass units beyond the protonated molecule (as opposed to stopping the scoring at protonated molecule). This ensures that the major peaks in the isotopic envelope around the protonated molecule are accounted for in scoring. The lower bound of the range (m/z 80) was chosen as representative of the minimum m/z value commonly employed in DART-MS for seized drug screening, and can be changed based on application.