Identifying Cereals through Elemental Analysis with Microwave Plasma Optical Emission Spectroscopy: Experiment for Analytical Chemistry Lab

Elemental analysis is performed in a variety of ways in food and environmental sciences; thus, we have designed an activity in which students gain experience with research-level lab techniques in a real-world context through the quantification of key elements in breakfast cereals using microwave plasma optical emission spectroscopy (MP-OES). The experiment described here is a skill building assignment to scaffold into more advanced projects with research-level instrumentation and in analytical chemistry courses. Students compare their results to the nutrition facts published by the distributors in order to identify their cereals, emphasizing precision and accuracy in instrumental analysis and good standard operating procedures (SOPs). Although cereals were chosen on the basis of the relevance of fortified minerals in this study, variations of this method may be used for the analysis of different food products. The student learning objectives of this experiment include developing SOPs for emission spectroscopy, creating and using standard curves to determine detection limits and elemental concentrations, presenting results using the proper format along with using statistical techniques such as standard deviation and method detection limit, and writing a report following the form of a technical journal article. MP-OES is a relatively new, sensitive, and inexpensive technique for elemental analysis, making it a practical choice for an undergraduate laboratory.