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ARS Home » Southeast Area » Stuttgart, Arkansas » Harry K. Dupree Stuttgart National Aquaculture Research Cntr » Research » Publications at this Location » Publication #153185
Title: A SIMPLE ASSAY TO COMPARE ZEOLITES OF UNKNOWN QUALITY

Author
item Mitchell, Andrew

Submitted to: Book of Abstracts World Aquaculture Society
Publication Type: Abstract Only
Publication Acceptance Date: 9/16/2003
Publication Date: 3/1/2004
Citation: Mitchell, A.J. 2004. A simple assay to compare zeolites of unknown quality [abstract]. Book of Abstracts World Aquaculture Society. p. 405.

Interpretive Summary:

Technical Abstract: Zeolite is often placed in fish shipping containers to reduce ammonia buildup when the shipments will be en route for several hours. Zeolites purchased from aquaculture industry suppliers vary in quality and without knowing information about the origin, type, and purity of the zeolites (information that is seldom available) the only way to determine the suitability of the products is through evaluations of their ability to remove ammonia. A simplified method for comparing the quality of zeolites purchased was developed for use by fishery extension specialists and by fish producers equipped with some basic scientific equipment. This method allows the user to select the best zeolite from those tested. Hach ammonia test kits, Model NI-8 (same as found in the commonly used Hach FF-1A kit) or Model NI-SA (no mercury in reagents) are used for the ammonia determinations. Ammonium sulfate (0.1 g) is dissolved in 1000 mL of either DW or DI using the stir bar. Ten g of zeolite is added in the solution and stirred for 20 min (keep stir bar moving). At 20 min, a 1:6 dilution of the zeolite-clouded and DW or DI water is made. The dilution is mixed (swirled or inverted a few times) and then tested for ammonia using either of the test kits mentioned above (following manufactures directions). The determination of actual total ammonia is not necessary because the readings directly from the 1:6 diluted samples will give the information needed to compare zeolite samples. The zeolite sample resulting in the lowest ammonia reading is best. Diluted sample readings from five zeolites tested ranged between 1.2 and 2.6 mg/L with the Hach Model NI-8 test kit and from 0.7 to 1.9 mg/L with the Model NI-SA test kit. The better zeolites tested in our study yielded diluted sample ammonia readings of less than 1.5 mg/L from both Hach kits.