ASTM C1345-08
Standard Test Method for Analysis of Total and Isotopic Uranium and Total Thorium in Soils by Inductively Coupled Plasma-Mass Spectrometry

Standard No.

ASTM C1345-08

Release Date

2008

Published By

American Society for Testing and Materials (ASTM)

Status

Withdraw

Latest

ASTM C1345-08

Scope

This test method measures the presence of uranium and thorium in soil that occurs naturally and as a result of contamination from nuclear operations and uranium ore processing. The reporting detection levels (RDLs) of total uranium and thorium are well below the normal background in soil. The normal background level for uranium is between 3 and 5 μg/g in most geographic areas and slightly higher for thorium. The ²³⁵U enrichment is also measured from an initial sample pass through the instrument. The other less abundant uranium isotopes (²³⁴U and ²³⁶U) are measured down to a typical soil background level after sample concentration and a second sample analysis. This allows for calculation of individual isotopic uranium and total uranium activity. The majority of the uranium activity results from ²³⁴U and ²³⁸U.

1.1 This test method covers the measurement of total uranium (U) and thorium (Th) concentrations in soils, as well as the determination of the isotopic weight percentages of ²³⁴U, ²³⁵U, ²³⁶U, and ²³⁸U, thereby allowing for the calculation of individual isotopic uranium activity or total uranium activity. This inductively coupled plasma-mass spectroscopy (ICP-MS) method is intended as an alternative analysis to methods such as alpha spectroscopy or thermal ionization mass spectroscopy (TIMS). Also, while this test method covers only those isotopes listed above, the instrumental technique may be expanded to cover other long-lived radioisotopes since the preparation technique includes the preconcentration of the actinide series of elements. The resultant sample volume can be further reduced for introduction into the ICP-MS via an electrothermal vaporization (ETV) unit or other sample introduction device, even though the standard peristaltic pump introduction is applied for this test method. The sample preparation removes organics and silica from the soil by use of a high temperature furnace and hydrofluoric acid digestion. Thus, this test method can allow for sample variability of both organic and silica content. This test method is also described in ASTM STP 1291. Since this test method using quadrupole ICP-MS was approved, advances have been made in ICP-MS technology in terms of improved sensitivity and lower instrument background as well as the use of collision or reaction cells (or both) and sector field mass spectrometers with single and multiple detectors. These advances should allow this test method to be performed more effectively but it is the user’s responsibility to verify performance.

1.2 The analysis is performed after an initial drying and grinding sample preparation process, and the results are reported on a dry weight basis. The sample preparation technique used incorporates into the sample any rocks and organic material present in the soil. The method of sample preparation applied differs from other techniques, such as those found in Practice C 999, which involve simply tumbling and sieving the sample; however, the user may select whichever technique is most appropriate to their needs.

1.3 The values stated in SI units are to be regarded as standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

ASTM C1345-08 Referenced Document

• ASTM C1255 Standard Test Method for Analysis of Uranium and Thorium in Soils by Energy Dispersive X-Ray Fluorescence Spectroscopy
• ASTM C859 Standard Terminology Relating to Nuclear Materials
• ASTM C998 Standard Practice for Sampling Surface Soil for Radionuclides
• ASTM C999 Standard Practice for Soil Sample Preparation for the Determination of Radionuclides
• ASTM D1193 Standard Specification for Reagent Water
• ASTM D1452 Standard Practice for Soil Investigation and Sampling by Auger Borings
• ASTM D1586 Standard Test Method for Penetration Test and Split-Barrel Sampling of Soils
• ASTM D1587 Standard Practice for Thin-Walled Tube Sampling of Soils for Geotechnical Purposes
• ASTM D2113 Standard Practice for Rock Core Drilling and Sampling of Rock for Site Investigation
• ASTM D2216 Standard Test Method for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass
• ASTM D3550 Standard Practice for Thick Wall, Ring-Lined, Split Barrel, Drive Sampling of Soils
• ASTM D420 Standard Guide to Site Characterization for Engineering Design and Construction Purposes
• ASTM E135 Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• ASTM E305 Standard Practice for Establishing and Controlling Spectrochemical Analytical Curves
• ASTM E456 Standard Terminology for Relating to Quality and Statistics
• ASTM E876 Standard Practice for Use of Statistics in the Evaluation of Spectrometric Data (Withdrawn 2003)
• ASTM E882 Standard Guide for Accountability and Quality Control in the Chemical Analysis Laboratory

ASTM C1345-08 history

• 2008 ASTM C1345-08 Standard Test Method for Analysis of Total and Isotopic Uranium and Total Thorium in Soils by Inductively Coupled Plasma-Mass Spectrometry
• 1996 ASTM C1345-96(2001) Standard Test Method for Analysis of Total and Isotopic Uranium and Total Thorium in Soils by Inductively Coupled Plasma-Mass Spectrometry
• 1996 ASTM C1345-96 Standard Test Method for Analysis of Total and Isotopic Uranium and Total Thorium in Soils by Inductively Coupled Plasma-Mass Spectrometry