1.1 This test method covers the determination of the concentration of uranium-235 and uranium-238 in urine using Inductively Coupled Plasma-Mass Spectrometry. This test method can be used to support uranium facility bioassay programs.

1.2 The method detection limits for ²³⁵U and ²³⁸U are 6 ng/L. To meet the requirements of ANSI N13.30, the minimum detectable activity (MDA) of each radionuclide measured must be at least 0.1 pCi/L (0.0037 Bq/L). The MDA translates to 47 ng/L for ²³⁵U and 300 ng/L for ²³⁸U. Uranium-234 cannot be determined at the MDA with this test method because of its low mass concentration level equivalent to 0.1 pCi/L.

1.3 The digestion and anion separation of urine may not be necessary when uranium concentration of  ng/L U are present.

Note 1: Warning--The ICP-MS is a source of intense ultraviolet radiation from the radio frequency induced plasma. Protection from radio frequency radiation and UV radiation is provided by the instrument under normal operation.

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.