Kg. Furton et al., RAPID-DETERMINATION OF URANIUM ON SOLID MATRICES BY SYNERGISTIC IN-SITU CHELATION SUPERCRITICAL-FLUID EXTRACTION AND UV ABSORPTION-SPECTROSCOPY, Analytica chimica acta, 304(2), 1995, pp. 203-208
The extraction and spectrophotometric quantitation of UO2(NO3)(2) . 6H
(2)O from different solid matrices is compared using ethanol solutions
and supercritical carbon dioxide containing various combinations of 2
-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5-octadione (FOD), tri-n-butylph
osphate (TBP), and ethanol. The matrix is shown to have a tremendous e
ffect on the extractability of ethanol from different solid matrices w
ith achievable recoveries as follows: polypropylene/polyester > glass
wool > cotton > clay. A synergistic increase in the recovery of U(VI)
from Kaolin is observed when ethanol is used in combination with FOD o
r a mixture of FOD and TBP. Compared to liquid extraction, the SFE met
hod yields higher recoveries, is significantly faster, is of equal or
greater precision, and greatly reduces the amount of organic solvents
used. Additionally, the UV absorption of the uranium . FOD complex is
linear over three orders of magnitude in concentration (ppb to ppm) an
d makes direct UV monitoring of the amount of uranium extracted feasib
le.