At-Home Laboratory Experiments for the Analytical Chemistry Curriculum
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Kelly Ambruso [1] ; Kathryn R. Riley [1]
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[1] Swarthmore College
Swarthmore College
Borough of Swarthmore, Estados Unidos
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- Localización: Journal of chemical education, ISSN 0021-9584, Vol. 99, Nº 2, 2022, págs. 1125-1131
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
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Resumen
In this communication, we describe five at-home laboratory experiments and demonstrations that complement a semester-long analytical chemistry curriculum. The experiments were successfully carried out by remote undergraduate students enrolled in a hybrid analytical chemistry course during the COVID-19 pandemic. Students used their personal smartphones to perform the spectrophotometric analyses and all other materials needed to carry out the experiments were assembled in a homemade laboratory kit with a total cost of 265 USD (with the potential for additional cost savings). The experiments centered on the analysis of a single analyte, Allura Red food dye, and spanned quantitative analysis by absorption spectroscopy, reverse-phase liquid chromatography, fluorescence quenching, and Brownian motion. Students used external calibration and the method of standard additions to determine the concentration of Allura Red in maraschino cherry juice to be 140 ± 40 and 130 ± 40 ppm, respectively. Students’ results were within the expected concentration range of 100–150 ppm. Qualitative spectroscopic and chromatographic analyses spurred robust discussion of the chemical principles underpinning the analytical techniques. Independent remote laboratory instruction was supported through weekly laboratory group meetings involving the remote students and course instructor. Group meetings enabled remote students to make connections with other students in the course, troubleshoot their data analysis in real-time with peer and instructor support, and reflect more deeply on their experimental work. Details about the kit contents, experimental results, best practices for implementation, and recommendations for future adaptation are described.
