A Spiral Approach to Chemical Concepts Using GC/MS

现代化学课程的一个明显需求是将化学概念的学习与现代仪器的使用结合起来。这些仪器可以用来教授化学概念，同时，学习化学概念使仪器不仅仅是神奇的黑色(或米色)盒子。有机化学教学的一个特殊需要是有一个有效的实验室方法来交流化学结构的概念，特别是构型异构体和立体异构体的概念。在分析化学中，需要更多地强调如何对与生物相关的样品进行分析，以及对于来自其他专业的化学和优等生，如何制定实验方案。本项目的目的是通过使用“螺旋”方法，在微型实验中应用现代气相色谱/质谱仪(GC/MS)仪器，教授分子结构的概念和分析方法。在螺旋式方法中，GC/MS实验和分子结构之间的关系将在一年或几年的几门实验室课程中重新讨论。这一目标是通过在有机化学和分析化学入门课程中引入五个使用GC/MS的新实验来实现的。新的有机实验是对经验式和分子式、结构异构性和立体异构性概念的创新方法。分析实验是一种新方法的一部分，该方法引入了学生设计的用于分析生物相关化学样品的协议。建议的实验在阐明化学概念方面具有重要意义，这些概念1)在现有的实验室手册中被忽视，2)在其他方面很难在微尺度上阐明，或3)与学生对传统化学实验室实验中经常被忽视的生物相关学科更感兴趣有关。

A distinct need in modern chemistry curricula is to integrate the learning of chemical concepts with the use of modern instrumentation. The instruments can be used to teach chemical concepts and, at the same time, learning the chemical concepts makes the instruments more than magical black (or beige) boxes. A specific need in teaching organic chemistry is to have an effective laboratory approach to communicate the concepts of chemical structure, especially the concepts of constitutional isomerism and stereoisomerism. In analytical chemistry, more emphasis needs to be placed on how analyses of biologically relevant samples are carried out, and, for chemistry and honors students from other majors, how experimental protocols are developed. The objective of the present project is to teach concepts of molecular structure and methods of analysis by application of modern gas chromatography/mass spectrometry (GC/MS) instrumentation in microscale experiments using a "spiral" approach. In the spiral approach, the relation between GC/MS experiments and molecular structure is re-visited in several laboratory courses spread out over one or more years. This objective is being accomplished by introducing five new experiments using GC/MS into introductory level organic and analytical chemistry courses. The new organic experiments are innovative approaches to the concepts of empirical and molecular formulas, constitutional isomerism, and stereoisomerism. The analytical experiments are part of a new approach to introduce student-designed protocols for the analysis of biologically relevant chemical samples. The proposed experiments are significant in illustrating chemical concepts that are I ) neglected in existing laboratory manuals, 2) otherwise difficult to illustrate in microscale, or 3) relevant to students more interested in biologically related subjects that are often neglected in traditional chemistry laboratory experiments.