An optical method for the determination of the isotopic composition of 1H2O/2H2O mixtures: Eu3+ luminescence lifetimes.
A spectroscopic method employing pulsed dye laser instrumentation is described for the determination of the 1H2O/2H2O composition of aqueous solutions by the measurement of reciprocal excited state lifetimes of EuEDTA-. The reciprocal lifetimes, gamma-1, of the 1H2O/2H2O mixtures increase linearly with the mole fraction of 1H2O. For EuEDTA- the relationship between gamma-1 and the mole fraction, chi H, of 1H2O in 1H2O/2H2O mixtures is expressed by the equation chi H = 0.37 gamma-1-0.152, with a sensitivity in chi H of +/- 0.02. The reciprocal lifetimes are independent of pH in the range 5.1 to 10.5, changes in ionic strength, and the type of buffer used in EuEDTA- containing solutions.
Cornwall
E H
EH
Department of Chemistry, Pennsylvania State University, University Park 16802.
Horrocks
W D
WD
D003903:Deuterium / Q000032:analysis*; D017666:Deuterium Oxide; D004492:Edetic Acid; D005063:Europium; D006859:Hydrogen / Q000032:analysis*; D008163:Luminescent Measurements; D013053:Spectrophotometry / Q000379:methods*; D014867:Water / Q000032:analysis
D014867:Water; D005063:Europium; D006859:Hydrogen; D004492:Edetic Acid; D003903:Deuterium; D017666:Deuterium Oxide