Introducing Students to Gas Chromatography–Mass Spectrometry Analysis and Determination of Kerosene Components in a Complex Mixture

Abstract

Gas chromatography−mass spectrometry (GC−MS) and GC−tandem MS (GC−MS/MS) are useful in many separation and characterization procedures. GC−MS is now a common tool in industry and research, and increasingly, GC−MS/ MS is applied to the measurement of trace components in complex mixtures. This report describes an upper-level undergraduate experiment to understand aspects of GC−MS analysis for a mixture of compounds, carry out a protocol for selected ion monitoring, and then determine a number of kerosene component classes using GC−MS. The first exercise analyzes a standard solution containing different compounds by using GC−MS, obtains characteristic ions, conducts library searching, calculates retention indices, and displays various extracted ion plots. Selected ion monitoring is then conducted based on retention time windows and characteristic ions for this sample. Kerosene is then analyzed by GC−MS to identify various classes of compounds using extracted ion plots to support compound class monitoring. The methods described in this report may be readily adapted to other kerosene components and other samples such as pesticides, essential oils, or other samples of interest.

Analysis of Pesticides in Plant Foods by QuEChERS and Gas Chromatography–Mass Spectrometry: An Undergraduate Laboratory Experiment

“…Experience of these practical analytical procedures is useful in academia, government, and industry. Laboratory experiments on the use of chromatography (gas and liquid)–mass spectrometry-based methods with applications in the chemical, , environmental, − forensic, biological, and clinical fields are being taught at the universities, but additional training and hands-on experience in these methods should be available in the analytical chemistry and instrumental analysis laboratory courses to provide invaluable skills and experience for undergraduate students.…”

Understanding Our Energy Footprint: Undergraduate Chemistry Laboratory Investigation of Environmental Impacts of Solid Fossil Fuel Wastes

“…In future years, we recommend an in-class activity prior to the lab exercise that has students analyze such complex mixture data by comparing retention times and ionization spectra, similar to ways in which we teach NMR, 33−35 or as Pacot et al recently suggested, through first analyzing a set of data from a standard mixture. 36 Classroom discussions and free-response surveys demonstrated that students gained an appreciation for the inherently complex nature of pollutant mixtures, and the potential risks posed at what students first think are "small" (ppm) concentrations. Said one student: "Even small concentrations of many of the PAHs found in this experiment have health risks... detection and regulation of even small amounts through quantitative analysis is important to ensure the health and safety of our water sources, crops, and the environment..."…”

“…This was the students’ first exposure to the analysis of complex mixtures via GC–MS, and they were initially overwhelmed by the myriad peaks on the chromatograms. In future years, we recommend an in-class activity prior to the lab exercise that has students analyze such complex mixture data by comparing retention times and ionization spectra, similar to ways in which we teach NMR, − or as Pacot et al recently suggested, through first analyzing a set of data from a standard mixture …”

Phytochemical Analysis and Determination of the Chemical Composition of Larvicidal Extracts of Black Pepper (Piper nigrum L.) Waste: An Undergraduate Chemistry Experiment

“…GC–MS is one of the most useful methods for quantitatively and qualitatively identifying sample constituents. The technique allows separating volatile components with good selectivity and sensitivity and provides structural information about compounds. − …”

“…The proposed experiment has the following strengths: it can be carried out in a short period, contributes to a better understanding of the theoretical concepts of GC–MS, and encourages students to use scientific research to propose solutions for real environmental problems. − …”