Concomitant species that appear at the same or very similar times in a mass-spectral analysis can clutter a spectrum because of the coexistence of many analyte-related ions (e.g., molecular ions, adducts, fragments). One method to extract ions stemming from the same origin is to exploit the chemical information encoded in the time domain, where the individual temporal appearances inside the complex structures of chronograms or chromatograms differ with respect to analytes. By grouping ions with very similar or identical time-domain structures, single-component mass spectra can be reconstructed, which are much easier to interpret and are library-searchable. While many other approaches address similar objectives through the Pearson’s correlation coefficient, we explore an alternative method based on a modified cross-correlation algorithm to compute a metric that describes the degree of similarity between features inside any two ion chronograms. Furthermore, an automatic workflow was devised to be capable of categorizing thousands of mass-spectral peaks into different groups within a few seconds. This approach was tested with direct mass-spectrometric analyses as well as with a simple, fast, and poorly resolved LC–MS analysis. Single-component mass spectra were extracted in both cases and were identified based on accurate mass and a mass-spectral library search.

By focusing on food and a pervasive contaminant, this experiment engages student interest and effort while providing essential instruction and experience. As institutions are challenged by existing and emerging budgetary constraints, this experiment offers a determination approach employing commonly available instrumentation, the graphite furnace atomic absorption spectrometer. The module provides a broad range of experiences: it introduces the lyophilizer, offers practice in a multistep novel digestion method, presents the theoretical foundation and practical application of atomic absorption spectroscopy, and provides an opportunity to record, calculate, and report findings. Students whose math skills are in development can complete it successfully because algebraic calculations are used at each stage of the materials’ examination. Finally, when their reports align with extensive international research, the lab offers students assurance of their growing scientific competence.