Interference-free determination of sub ng kg-1 levels of long-lived 93Zr in the presence of high concentrations (μg kg-1) of 93Mo and 93Nb using ICP-MS/MS.

摘要: Long-lived high abundance radionuclides are of increasing interest with regard to decommissioning nuclear sites and longer term waste storage disposal. In many cases, no routine technique is available for their measurement in low-level (ng kg−1) environmental samples. Recent advances ICP-MS technology offer attractive features the selective sensitive determination a wide range long-lived radionuclides. this work, inductively coupled plasma-tandem mass spectrometry (ICP-MS/MS)-based methodology, suitable accurate determinations 93Zr at very low levels presence (μg isobaric interferents 93Nb 93Mo (often present samples), reported first time. Additionally, novel systematic strategy method development based on use non-radioactive isotopes proposed. It relies gas-phase chemical reactions different molecular ion formation achieve interference removal. Using cell gas mixtures NH3/He/H2 or H2/O2, shifts, signal from interferences were suppressed by up 5 orders magnitude. The achieved limit detection was 1.3 × 10−5 Bq g−1 (equivalent 0.14 ng kg−1). sample analysis time 2 min, which represents significant improvement terms throughput, compared liquid scintillation counting methods. described here can be used measurements environmentally relevant levels. also combined radiometric techniques towards standardisation measurements.