Isotopic measurements of uranium using inductively coupled plasma cavity ringdown spectroscopy.
Inductively coupled plasma cavity ringdown spectroscopy (ICP-CRDS) is applied to isotopic measurements of uranium. We have successfully obtained the isotopic-resolved spectra of uranium at three different atomic/ionic transition lines, 286.57, 358.49, and 409.01 nm. Of the three lines, the largest isotope shift of approximately 9 pm was measured at the 286.57 ionic line. Isotopic-resolved spectra were recorded in ratio of 1:1 (235U/238U, 2.5 micrograms/mL) and at the natural abundance ratio of 0.714% (235U/238U, 1.25 micrograms/mL 235U). The smallest measurable isotope shift of approximately 3 pm was determined for the 409.01 nm ion spectral line. Detection limits (DL) were obtained under optimized ICP operating conditions to be in the range of 70-150 ng/mL, except for the 238U component of the 286.57 nm line (300 ng/mL). This latter result was determined to be due to a strong, previously unreported, absorption interference from the argon plasma. The 235U isotope component (DL 70 ng/mL) was found to be unaffected. This work demonstrates the applicability of ICP-CRDS for uranium isotopic measurements. The potential of development of a field-deployable, on-line uranium isotope monitor using plasma-CRDS is discussed.
Wang
Chuji
C
Diagnostic Instrumentation & Analysis Laboratory, Mississippi State University, 205 Research Blvd., Starkville, Mississippi 39759, USA. wang@dial.msstate.edu
Mazzotti
Fabio J
FJ
Miller
George P
GP
Winstead
Christopher B
CB
D005740:Gases / Q000032:analysis*; D006358:Hot Temperature; D007554:Isotopes / Q000032:analysis* / Q000737:chemistry / Q000145:classification*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013057:Spectrum Analysis / Q000379:methods*; D014501:Uranium / Q000032:analysis* / Q000737:chemistry / Q000145:classification*
D005740:Gases; D007554:Isotopes; D014501:Uranium