Incorporating Gas Chromatography and CHN Elemental Analysis into the Undergraduate Science Laboratory Curricula: A Multidisciplinary Approach

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Chemistry (12) In order to improve the laboratory experience of our students, we are incorporating Gas Chromatography (GC) and carbon, hydrogen, nitrogen (CHN) Elemental Analysis techniques into the science laboratory curricula at Arizona Western College and Northern Arizona University-Yuma. Several published chemistry, microbiology, environmental science, and agricultural science experiments are being adapted into the four discipline's laboratory curricula. Chemistry students use the instrumentation to monitor the uptake of a nitrogen-based fertilizer into various vegetative and reproductive organs of wheat during seed development and to determine a product's empirical formula, its percent purity, and the efficiency of recrystallization. Agricultural Science students use the instrumentation to carry out a spatiotemporal soil C:N analysis study at various soil depths in a recently tilled but still fallow corn and alfalfa fields. They examine the fate and transport of nematicides as a function of soil depth and soil type and also study the difference in autocatalytic production rates of ethylene gas- a plant growth regulator- in various foods. Environmental Science students use the GC to measure carbon monoxide emissions from vehicle exhaust and measure the rate of production of greenhouse gases from soil. Microbiology students use the instrumentation to quantify soil microbial biomass. The multidisciplinary use of the Elemental Analyzer and GC has provided us an opportunity to incorporate new labs into the curriculum and hence expand topic coverage in the classroom. The instrumentation now allows the faculty to teach topics that were relegated to lecture because of non-existent instrumentation capacity and also gives students hands-on experience with modern instrumentation and methodology. It is anticipated that the project's emphases on the relevancy of science to everyday life, hands-on instrument experience, and using the surrounding desert environment as a laboratory provide our students a valuable laboratory experience that is consistent with current science educational trends and practices.