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.

Magnetic stirrers and hot plates are key components of science laboratories. However, these are not readily available in many developing countries due to their high cost. This article describes the design of a low-cost magnetic stirrer with hot plate from recycled materials. Some of the materials used are neodymium magnets and CPU fans from discarded computers and recycled electrical components from old circuit boards. This prototype was compared with a commercial magnetic stirrer with hot plate. It was noted that high temperatures were reached at similar rates, and the stirring speed was also comparable between the two. With this prototype, which costs 80% less than commercials ones, magnetic stirrers with hot plate can be readily available to enhance teaching and learning in science laboratories that need them most.

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