The use of Complementary Instrumentation to Enhance Critical Thinking in Chemical Analysis

Eastern Illinois University, Charleston IL

Investigators

Abstract

Chemistry (12) The teaching of undergraduate instrumental analysis is somewhat problematic. Recent research in teaching and learning suggests that superior results are obtained using an active learning (problem based) approach. However, a solely problem based approach may not allow time to adequately address the fundamental concepts of analytical chemistry. This project is introducing problem solving and critical thinking, primarily in instrumental analysis, without a significant sacrifice in fundamental course content. The acquisition of selected equipment (EDXRF - energy dispersive x-ray fluorescence; spectrofluorometer; microwave digestion) to augment existing instrumentation will facilitate the incorporation of a problem based laboratory approach into the analytical curriculum. Active-learning, inquiry-based projects are being used to solve analytical problems with complementary instrumentation. The instrumental analysis laboratory is divided into four sections. The first section involves fundamental concepts of data collection and manipulation, including signal-to-noise ratio, detection limits, resolution, spectrometer design and statistics. Within the other three sections, students answer specific questions by analyzing real samples using complementary instruments. Students are responsible for arriving at the most efficient procedure to answer the questions. One section involves chromatographic analyses (GC, HPLC, GC/MS), a second section focuses on elemental analysis (XRF and AA with microwave digestion sample preparation), while a third section involves molecular spectroscopy using UV/Vis and molecular fluorescence spectroscopic analyses. Students are required to complete two of the three latter sections. For each completed section, each student generates a report. Students also discuss how they solved their assigned problem, justify their procedure, and critically discuss the advantages and disadvantages of the instruments used for their analysis. Students are thus being exposed to a variety of modern instrumental methods, and learn to think critically and fundamentally about those methods, and to solve real problems. Many of the experiments are based on recent articles in the pedagogical literature (J. Chemical Education, texts) and are adapted from those sources for implementation into the local context. Other courses (non-analytical) affected by the introduction of this new instrumentation include physical chemistry, undergraduate research, and a general education chemistry course with a high population of elementary education majors.