A simple setup for measuring the amount of potassium in foods is described. A 3-in. NaI detector is used to measure samples that are 3000 cm3 in size. With moderate shielding, the potassium content can be measured down to a detection limit of a few parts per 10 000.
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We used pure prune juice, whose label listed the potassium content at 0.2%.
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Our soil sample data are available on the web at http://www.csupomona.edu/pbsiegel/ . Spectra from our 3-in. NaI detector in ASCII format from various sites in the Los Angeles area can be downloaded.
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© 1999 American Association of Physics Teachers.
1999
American Association of Physics Teachers
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