A. Ramesh et al., SUB-STOICHIOMETRIC ISOTOPE-DILUTION ANALYSIS FOR THE DETERMINATION OFSELENIUM BY LIQUID SCINTILLATION-COUNTING, Analyst, 119(9), 1994, pp. 2067-2070
A sensitive and selective sub-stoichiometric isotope dilution method f
or the determination of trace amounts of selenium is described. The me
thod is based on the extraction of the selenium-dithizone complex with
a sub-stoichiometric amount of dithizone into toluene from 7 mol l(-1
) hydrochloric acid. The activity of the extracted complex was measure
d by liquid scintillation counting and the counting efficiency was fou
nd to be 40%. The calibration graph was linear in the range 0-10 mu g
of selenium in a final volume of 10 ml. As little as 0.01 mu g of sele
nium can be determined in a total volume of 10 ml. The interferences d
ue to several ions were overcome by using an aluminium hydroxide colle
ction procedure.