The design and experimental execution of external standard and standard addition calibrations for analyte quantification are not easy concepts for students to fully grasp, including understanding advantages, disadvantages, and timing considerations of each method. In order to gain experience with both calibration methods students were directed through a multiweek, guided-inquiry, experiment to quantify an analyte in a complex matrix while also comparing the spectroscopic techniques of absorbance and fluorescence. Students used one absorbance and one fluorescence method to quantify the analyte of interest and statistically compared the results. If the results did not match, students came up with a plan address the different result and to account for possible matrix effects in the sample to accurately determine the analyte concentration. Students also shared and relied on class data to fully assess the different types of spectroscopic techniques/instrumentation and answer questions regarding the sensitivity, selectivity, dynamic range, and detection limits. Students approached the problem from different angles, with varying success. In the end, students gained experience with a “real world” type of analysis that required careful planning and execution for successful analyte quantification.

Experiences teaching calibrations, matrix effects, and sample nalysis through a guided-inquiry spectroscopy laboratory experiment

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.