Kinetics and Pathways of the Aqueous Photolysis of Pharmaceutical Pollutants: A Versatile Laboratory or Remote Learning Investigation

Autor/inn/en	Buth, Jeffrey M.; Ossola, Rachele; Partanen, Sarah B.; McNeill, Kristopher; Arnold, William A.; O'Connor, Meghan; Latch, Douglas E.
Titel	Kinetics and Pathways of the Aqueous Photolysis of Pharmaceutical Pollutants: A Versatile Laboratory or Remote Learning Investigation
Quelle	In: Journal of Chemical Education, 98 (2021) 7, S.2411-2418 (8 Seiten)Infoseite zur Zeitschrift PDF als Volltext Verfügbarkeit
Zusatzinformation	ORCID (Buth, Jeffrey M.) ORCID (Ossola, Rachele) ORCID (Partanen, Sarah B.) ORCID (McNeill, Kristopher) ORCID (Arnold, William A.)
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0021-9584
DOI	10.1021/acs.jchemed.0c01398
Schlagwörter	Kinetics; Pharmacology; Water Pollution; Laboratory Experiments; Chemistry; Science Activities; Outreach Programs; Distance Education; Science Experiments; Laboratory Equipment + Suchen Sie Ihr Suchwort? Kinetik; Arzneikunde; Gewässerverschmutzung; Laboratory work; Laborarbeit; Chemie; Jobcoaching; Distance study; Distance learning; Fernunterricht; Laborausstattung
Abstract	In this laboratory experiment, students explore the aquatic photochemical fate of ranitidine and cimetidine, two common pharmaceutical pollutants found in wastewater. It provides an engaging environmental context for students to develop knowledge of reaction kinetics and photochemistry as well as skill in using analytical instrumentation. This versatile experiment consists of two basic modules, three optional advanced modules, and additional add-ons that may be performed in various combinations to meet the unique learning objectives of general, analytical, physical, and environmental chemistry courses and science outreach activities. It may be performed as a traditional lab experiment or as an entirely remote exercise with an increased focus on data analysis and interpretation using provided example data sets. All of the photolysis experiments are carried out by preparing solutions of ranitidine or cimetidine in various matrices, irradiating the samples, and periodically removing subsamples for HPLC analysis of the compound of interest. Pseudo-first order kinetic plots are then generated to determine rate constants that are used to draw conclusions about photolysis pathways or to calculate additional kinetic parameters. In the two basic modules, cimetidine is found to degrade appreciably only when irradiated in the presence natural organic matter (NOM), indicating an indirect, photosensitized degradation pathway. In contrast, ranitidine degrades in pure buffer and in the presence of NOM with comparable rate constants, highlighting the predominant role of direct photolysis. In the advanced modules, students calculate ranitidine direct photolysis quantum yields and examine the significance of singlet oxygen as a photochemically produced reactive intermediate. The two basic modules may be completed in two 3 hour lab periods, while the advanced modules require additional time. This experiment requires only an HPLC instrument, inexpensive chemicals, and common glassware and lab equipment if performed in person and a personal computer if performed remotely. (As Provided).
Anmerkungen	Division of Chemical Education, Inc. and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail: eic@jce.acs.org; Web site: http://pubs.acs.org/jchemeduc
Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2024/1/01