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。在有机化学教学中，有一个特别的需要，就是要有一个有效的实验方法来传达化学结构的概念，特别是构分异构和立体异构的概念。在分析化学中，更多的重点需要放在如何分析生物相关的样品，以及，对于化学和其他专业的荣誉学生，如何制定实验方案。本计划的目的是教授分子结构的概念，以及使用“螺旋”方法在微尺度实验中应用现代气相色谱/质谱（GC/MS）仪器进行分析的方法。在螺旋方法中，GC/MS实验与分子结构之间的关系在一年或几年的实验课程中被重新审视。通过在入门级有机化学和分析化学课程中引入五个新的GC/MS实验来实现这一目标。新的有机实验是创新的方法，以经验和分子式的概念，构成异构，立体异构。分析实验是引入学生设计的生物相关化学样品分析方案的新方法的一部分。提出的实验在说明化学概念方面具有重要意义，这些概念是1)在现有的实验室手册中被忽视的，2)在微观尺度上难以说明，或3)与学生更感兴趣的生物学相关主题相关，而这些主题在传统的化学实验室实验中经常被忽视。

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.