Summary

In this lesson, students will learn about the development of Gas Chromatography-Mass Spectrometry (GC-MS) and how it used today. There are a series of activities to help promote literacy in the science classroom related to the reading. Through these activities students will learn how to interpret a skeletal structure, as well as the names and structures of several organic functional groups. Additionally, they will examine and evaluate a mass spectrum. This lesson could be easily used as plans for a substitute teacher, as most of the activities are self-guided.

Grade Level

High School

NGSS Alignment

This lesson will help prepare your students to meet the performance expectations in the following standards:

• HS-PS2-6: Communicate scientific and technical information about why the molecular-level structure is important in the functioning of designed materials.
• Scientific and Engineering Practices:
  • Asking Questions and Defining Problems
  • Analyzing and Interpreting Data
  • Engaging in Argument from Evidence
  • Obtaining, Evaluating, and Communicating Information

Cross cutting concepts:

• Patterns
• Scale, proportion, and quantity
• Structure and function

Objectives

By the end of this lesson, students should be able to:

• Describe the sequence of events that lead to development of the GC-MS.
• Differentiate between the purpose of the Gas Chromatography and the Mass Spectrometer.
• Explain what a skeletal structure is for an organic compound.
• Recognize and name simple organic functional groups.
• Compare GC-MS data to determine if compounds are the same.
• Explain what information can be determined from GC-MS.

Chemistry Topics

This lesson supports students’ understanding of:

• Separating Mixtures
• Identifying an Unknown
• Organic Chemistry
• Functional Groups
• Gas Chromatography
• Mass Spectroscopy
• Data Analysis

Time

Teacher Preparation: 10 minutes
Lesson: Approximate times for students to complete each activity in the lesson:

• Anticipation guide: 10-20 minutes
• Reading: 20 minutes
• History exercise: 20-30 minutes
• Banana Candy Video: 20-25 minutes
• Organic Structures: 15-20 minutes
• Looking at Spectra: 15-20 minutes

Materials

• Computer with internet access
• Reading document and any of the student handouts that accompany it that you want to include.

Safety

• No specific safety precautions need to be observed for this lesson.

Teacher Notes

Background:

• This lesson plan was originally developed through the American Chemical Society’s National Historic Chemical Landmarks Program. Under this program, ACS grants Landmark status to seminal achievements in the history of the chemical sciences and provides a record of their contributions to chemistry and society in the United States.

Lesson Overview:

The lesson includes multiple components as outlined individually below. It is assumed that the student has some knowledge of chromatography. The Reading is essential for all of the activities. Teachers can choose to do one or all of the included activities, however, the lesson is generally designed to be performed in the sequence described and for the students to progress at their own pace. Student handouts and corresponding answer keys are provided for each item described below:

• Activity: Anticipation Guide
  • Anticipation guides help engage students by activating prior knowledge and stimulating student interest before reading. If class time permits, discuss students’ responses to each statement before reading each article. Then, while they read, students should look for evidence supporting or refuting their initial responses.

• Reading: GC-MS: Purification and Identification Made Possible

• Activity: History Exercise
  • Students will complete a short review of the sequence of events from the article. Then they will explore the ACS Landmarks Timeline, providing an opportunity to learn about an additional Landmark that they find interesting.
  • It is suggested that students be given a limited amount of time for reading and writing their paragraph. This extension could also be moved to the very end of the lesson.
• Activity: Banana Candy Video
  • Student will watch the ACS Reactions video, Why Doesn’t Banana Candy Taste Like Banana? While watching students will answer a set of questions. The video describes the different parts of GC-MS and helps to answer several questions.
• Activity: Organic Structures
  • In this activity students are introduced to skeletal structures and organic functional groups.
• Activity: Examination of Data
  • Students learn how to evaluate a mass spectrum and are given an opportunity to evaluate GC-MS data.

• Related classroom resources from the AACT library that may be used to further teach this topic:
  • Activity: T-Shirt Chromatography
  • Animation: Separating Mixtures
  • Lab: Chemicals, Chromatography and Crime!
  • Lab: Using Paper Chromatography to Separate the Pigments Found in Ink
  • News Post from AACT: JChemEd Activity uses Boiling Point Investigation and Gas Chromatography to Teach Intermolecular Forces in AP Chem

• Other useful links:
  • Chemical & Engineering News: Portable Chemical Analysis for Drug Investigations Promises More Reliable and Just Results
  • Chemical & Engineering News: Mobile Mass Spectrometry Lab Could Help find trafficked wood within the timber trade
  • National Historic Chemical Landmark: Gas Chromatography-Mass Spectrometry