ASTM C1614-05(2010) PDF

1.1 This practice covers the separation and preconcentration of neptunium-237 (²³⁷Np), thorium-232 (²³²Th), uranium-235 (²³⁵U) and uranium-238 (²³⁸U) from urine followed by quantitation using ICP-MS.

1.2 This practice can be used to support routine bioassay programs. The minimum detectable concentrations (MDC) for this method, taking the preconcentration factor into account, are approximately 1E-2Bq for ²³⁷Np (0.38ng), 2E-6Bq for ²³²Th (0.50ng), 4E-5Bq for ²³⁵U (0.50ng) and 6E-6Bq for ²³⁸U (0.48ng).

1.3 This standard does not purport to address all of the safety problems, 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.