LEGO Exercise

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This module introduces students to the relationship between chromatograms and mass spectra using hands-on group work with molecules built from LEGO™ bricks and environmental case studies involving the analysis of pesticides by GC-MS and oil spill dispersant chemicals by LC-MS/MS.

The first of three in-class exercises guides students through the process of creating total and extracted ion chromatograms and mass spectra using molecules built from LEGO™ bricks. The goals of this hands-on exercise are to build a solid conceptual understanding of mass spectral peak origin, interpretation, and connection to the chromatogram. Two environmental case studies, involving pesticides (GC-MS) and oil spill dispersants (LC-MS/MS), reinforce the relationships between chromatography and mass spectrometry, explore the mass spectrum of an isotopically-labeled internal standard, require recall of the factors influencing peak broadening, and introduce the idea of tandem mass spectrometry. The module assumes students have had prior exposure to chromatographic separations, the basic block diagram of a mass spectrometer, and common ionization mechanisms (e.g., EI and ESI).

Resources

• In-Class Exercises (Word, PDF)
• Data Sheet (Excel, PDF)
• Mass Spectra and Total Ion Chromatogram Simulation (Excel)
• Mass Spectra Simulation (PDF)
• Total Ion Chromatogram Simulation (PDF)
• Key (Word, PDF)
• Instructor’s Guide (Word, PDF)