Ultra-low-level determination of (236)U in IAEA marine reference materials by ICPMS and AMS.

The development of analytical procedures for the measurement of ultra-low levels of (236)U in marine samples using high-resolution inductively coupled plasma mass spectrometry (HR-ICPMS) and accelerator mass spectrometry (AMS) techniques are discussed and results are presented for IAEA reference materials-marine sediments (IAEA-135, 306, 384 and 385), marine biota (IAEA-134 and 414) and seawater (IAEA-381), collected in areas affected by nuclear reprocessing plants and nuclear weapons tests. The obtained minimum detection limit of the (236)U/(238)U atom ratio was 1x10(-8) for AMS and 1x10(-6) for HR-ICPMS.