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ERIC Number: EJ1002944
Record Type: Journal
Publication Date: 2012-Oct
Pages: 4
Abstractor: As Provided
Reference Count: 33
ISSN: ISSN-0021-9584
Supercritical Fluid Extraction versus Traditional Solvent Extraction of Caffeine from Tea Leaves: A Laboratory-Based Case Study for an Organic Chemistry Course
Schaber, Peter M.; Larkin, Judith E.; Pines, Harvey A.; Berchou, Kelly; Wierchowski, Elizabeth; Marconi, Andrew; Suriani, Allison
Journal of Chemical Education, v89 n10 p1327-1330 Oct 2012
In this case-based laboratory, an instrument sales person attempts to convince an analysis laboratory of the virtues of supercritical fluid extraction (SFE). The sales person deals directly with the laboratory technicians who will make the decision. Arrangements are made to have SFE instrumentation brought into the laboratory for a comparative study. The extraction and gravimetric determination of caffeine from finely cut tea leaves is chosen as the "test". The technicians are divided into two groups. Group A performs a traditional solvent extraction using methylene chloride (CH[subscript 2]Cl[subscript 2])/alkaline water and group B using a SFE method. Students play the role of laboratory technicians and use the data collected to determine which method they would choose considering several variables and issues. It puts the student into a real-world situation and requires them to apply their critical-thinking skills to make a decision. This case-based laboratory exposed second-year science students to a new technology, provided them with an opportunity to compare and contrast competitive methods, and promoted green chemistry initiatives. An unexpected instrument anomaly affected several students in Group B. How this anomaly was reflected in student assessment of this case-based laboratory is also presented.
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:; Web site:
Publication Type: Journal Articles; Reports - Research
Education Level: Higher Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A