Laser-Induced Breakdown Spectroscopy for Qualitative Analysis of Metals in Simulated Martian Soils.

This laboratory introduces students to laser-induced breakdown spectroscopy (LIBS) for the analysis of metals in soil and rock samples. LIBS employs a laser-initiated spark to induce electronic excitation of metal atoms. Ensuing atomic emission allows for qualitative and semiquantitative analysis. The students use LIBS to analyze a series of standard samples that contain various elements and construct a table of emission line wavelengths for each element analyzed. Students then identify metals in various soil and rock samples. Students gain valuable experience in qualitative analysis using an important spectroscopic tool, while gaining hands-on experience with a spectrometer employing a high energy laser pulse as an excitation source. The LIBS spectrometer is applicable to upper and lower division chemistry courses and can be used as an effective demonstration tool for students in 5th to 12th grade.