NEMI Method Summary

Method Summary Information

Method Number: 3H-04-RC Media: WATER
Revision: EML Procedures Manual HASL-300, Volume 1, 28th Ed.(1997)
Method Source: U.S. Department of Energy Environmental Measurements Laboratory
Analytes in this method
Subcategory: RADIOCHEMICAL
Official Name: TRITIUM IN WATER - LIQUID SCINTILLATION COUNTING
Descriptive Name Tritium in Water - Liquid Scintillation Counting
Source Info: U.S. Department of Energy Environmental Measurements Laboratory
201 Varick St.
5th Floor
New York, NY 10012-4811
Citation: DOE EML Procedures Manual HASL-300, Volume 1, 28th Ed.(1997)
407581 Byte file
Brief Method
Summary:
 The 3H spectral range or window setting is first defined. The counting efficiencies are then determined by using efficiency curves (quench curves). The efficiency curve is a plot of the counting efficiency as a function of the quench index parameter (QIP). The QIP is also known as the automatic external standardization (AES) number or the transformed spectral index of the external standard (tSIE). A sample aliquot is prepared with a measured volume of a scintillation cocktail that is then placed in a programmed LS counter for spectrum analysis.
Scope And
Application:
 The procedure is used for the rapid determination of tritium by liquid scintillation (LS) spectrometry. It applies to all clear liquid samples and it can be completed in a short period (1 to 2 h) once efficiency curves have been established. The procedure is designed for a Tri-Carb 2250CA LS counter using Insta-Gel XF cocktail and it requires distillation of the samples so that they are free of salts and other interfering radionuclides.
Applicable
Conc Range:
 None given.
Interferences: (A) 3H Distillation: Perform a 3H distillation if information more accurate than gross tritium is needed.
(B) High Count Rates: Reanalyze samples with excessively high count rates (e.g., > 1,000,000 counts min-1) using less sample material. (Note: When using this procedure, the calculated 3H concentration may be higher than the actual concentration because of possible interferences from other low-energy beta emitters and the beta continuum of high energy beta particles.)
(C) Efficiency Drops - Add several drops of 30% H2O2 to the vial to bleach the sample if quenching causes the efficiency to drop to one fourth of the highest efficiency. (Note: Deep color in the samples may cause severe quenching that will lower the counting efficiency.)
(D) Cross contamination: High-level and low-level samples should be processed in independent batches to minimize possibility of cross contamination.
QC Requirements: QC samples should be analyzed to ensure required limits of precision and accuracy are being met. QC samples include instrument calibration standards, blank samples, control samples, an "spiked" samples.
Sample Handling: None given.
Max Holding Time:
 None given.
 
Relative Cost: $51 to $200
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