Project-Based Learning in Undergraduate Environmental Chemistry Laboratory: Using EPA Methods To Guide Student Method Development for Pesticide Quantitation

Presented is a project-based learning (PBL) laboratory approach for an upper-division environmental chemistry or quantitative analysis course. In this work, a combined laboratory class of 11 environmental chemistry students developed a method based on published EPA methods for the extraction of dichlorodiphenyltrichloroethane (DDT) and its environmental degradation products (dichlorodiphenyldichloroethane [DDD] and dichlorodiphenyldichloroethylene [DDE]) through Soxhlet extraction and quantitation using gas chromatography mass spectrometry (GC MS). From the derived procedures, the students spent the remainder of the semester performing extractions and analyses to detect pesticide drift from the San Joaquin Valley of California into the Sierra Nevada Mountain Range. The EPA methods used allow for a multitude of research-level questions which could be answered within a similar course with a specific question appropriate to student interest and regional environmental issues. This pedagogical approach provided numerous teaching moments regarding the pitfalls of research and low-level quantitation in environmental samples, as well as development opportunities for student teamwork skills as each individual focused on a specific aspect of the project throughout the semester.