Determining actinides in urine is vital for occupational
exposure
monitoring and radiological emergency response because of the toxicity
and radiological dose effects of actinides on human health. Traditional
radiochemistry analytical methods used to determine actinide concentrations
in urine are time-consuming (sample analysis takes several days) and
are hindered by a variety of technical and instrumentation-related
obstacles. A high-throughput, fully automated, precise, and accurate
in-line method was developed for determining five actinides (241Am, 239Pu, 237Np, 232Th,
and 238U) at ng/L levels in urine using extraction chromatography
combined with quadrupole inductively coupled plasma mass spectrometry
(EC-ICP-MS). In this method, the five actinides were successfully
separated with the required sensitivity, peak shape, and resolution
using a simplified single Eichrom TRU column with a Dionex ICS-5000
system. The separated actinides were subsequently injected into an
in-line PerkinElmer (PE) NexION 300D ICP-MS for quantitative determination.
The sample-to-sample run time was 23 min for automatic chemical separation
and quantification using only 0.5 mL of urine. The limits of detection
(LOD) obtained using this method were 0.015, 0.022, 0.039, 4.5, and
2.4 ng/L for 241Am, 239Pu, 237Np, 232Th, and 238U, respectively. The method routinely
had a chemical yield of >84% as well as a linearity (R
2) coefficient of ≥0.999 for the calibrators. The
method proved to be rapid, reliable, and effective for actinide quantification
in urine and therefore is appropriate for radiological emergency response
incidents.