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2000
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In the Laboratory
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The Determination of Ergosterol in Environmental Samples. An Interdisciplinary Project Involving Techniques of Analytical and Organic Chemistry
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Eugene J. Volker, Dan DiLella, Kim Terneus, Carson Baldwin, and Ilona Volker
Department of Chemistry, Shepherd College, Shepherdstown, WV 25443
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December 2000
Vol. 77 No. 12
p. 1621
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| Abstract |
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In this undergraduate laboratory experiment, a naturally formed steroid that is an important environmental indicator of biological activity is extracted and quantified. The target compound is ergosterol, a steroid found only in fungi and an accepted measure of fungal biomass. Maple leaves were used as a representative sample, but the procedure can be extended to soils, fruits, and grains. The environmental sample is first saponified with methanolic KOH to release ergosterol from any bound forms. Next, the steroid is transferred into pentane to separate it from the polar components of the initial extract. After evaporation of the pentane, the residue containing the steroid is dissolved in methanol and filtered. This solution is analyzed on an HPLC instrument equipped with a reversed-phase column. Typical values for ergosterol in the maple leaf samples analyzed ranged from 22 to 240 mg/g of dry leaf. Leaves collected shortly after falling have low values, and those collected later have progressively higher values. The experiment has been tested in Analytical Chemistry, Environmental Chemistry, and Organic Chemistry classes and can be performed in two 3-hour laboratory periods.
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| Supplement |
Laboratory procedure and instructor notes are available.
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 Contents |
JCE2000p1621W_1.doc, JCE2000p1621W_2.doc (Microsoft Word 97, Windows)
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| Download |
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| More Information |
Citation |
Volker, Eugene J.; DiLella, Dan; Terneus, Kim; Baldwin, Carson; Volker, Ilona. J. Chem. Educ. 2000 77 1621.
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Keywords |
Analytical Chemistry; Chromatography; Environmental Chemistry; Laboratory Instruction; Natural Products; Organic Chemistry
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History |
Created:
Last Updated: |
November 3, 2000
August 31, 2005
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2000
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December
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