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11 October 2008

Answer to Question #1153 Submitted to "Ask the Experts"

Category: Instrumentation and Measurements — Instrument Calibration (IC)

The following question was answered by an expert in the appropriate field:

What methods are available for the problems associated with liquid scintillation counting (LSC) for tritium when the sampling environment is laden with a variety of zinc sulphide phosphorescent powder?

The Environmental Protection Agency's regulations in 40 CFR 141.16 "Maximum contaminant levels for beta particle and photon radioactivity from man-made radionuclides in community water systems" set a limit of 20,000 pCi L^-1 for tritium in drinking water. In the same 40 CFR 141 drinking water regulations, the Standard Methods for the Examination of Water and Wastewater, 19^th Edition, is noted for various water analysis methods. My 13^th edition of Standard Methods has an approach for tritium involving a sample distillation and dark adaptation, then LSC. If the water is driven off the sample and then this method applied, it should eliminate any chemiluminescence. Standard Methods may be purchased from the American Public Health Association, 1015 Fifteenth Street, NW, Washington, DC 20005.

David J. Allard, CHP

Answer posted on 28 August 2001. The information and material posted on this Web site is intended as general reference information only. Specific facts and circumstances may alter the concepts and applications of materials and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice specific to whatever facts and circumstances are presented in any given situation. Answers are correct at the time they are posted on the Web site. Be advised that over time, some requirements could change, new data could be made available, or Internet links could change. For answers that have been posted for several months or longer, please check the current status of the posted information prior to using the responses for specific applications.