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

为了提高学生的实验室体验，我们正在将气相色谱（GC）和碳、氢、氮（CHN）元素分析技术纳入亚利桑那西部学院和北亚利桑那大学尤马分校的科学实验室课程。一些已发表的化学、微生物学、环境科学和农业科学实验正在被改编成四个学科的实验课程。化学专业的学生使用该仪器监测小麦种子发育过程中氮肥进入各种营养和生殖器官的情况，并确定产品的经验公式、纯度百分比和再结晶效率。农业科学专业的学生使用该仪器在最近耕作但仍处于休耕状态的玉米和苜蓿田的不同土壤深度进行了时空土壤C:N分析研究。他们研究了杀线虫剂的命运和运输作为土壤深度和土壤类型的函数，还研究了不同食物中乙烯气体（一种植物生长调节剂）自催化产率的差异。环境科学专业的学生使用气相色谱来测量汽车尾气中的一氧化碳排放量，并测量土壤中温室气体的产生速度。微生物学学生使用仪器来量化土壤微生物生物量。元素分析仪和气相色谱的多学科使用为我们提供了一个将新实验纳入课程的机会，从而扩大了课堂上的主题覆盖范围。仪器现在允许教师讲授那些由于不存在仪器能力而被归入课堂的主题，并且还为学生提供了现代仪器和方法的实践经验。预计该项目强调科学与日常生活的相关性，动手仪器体验，并将周围的沙漠环境作为实验室，为我们的学生提供与当前科学教育趋势和实践相一致的宝贵实验室体验。

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.