Determination of the deuterium/hydrogen ratio in gas reaction products by laser-induced breakdown spectroscopy

This paper reports the first application of laser-induced breakdown spectroscopy technique (LIBS) to the determination of deuterium/hydrogen numeric ratio (beta) in the headspace gases, essentially HD+H-2, that are generated by the hydrolysis of NaBD4-NaBH4 mixtures (molar fraction of NaBD4, x=50-100%) in acidic H2O media (O < pH < 1). The LIBS measurement of beta can be easily achieved with a coefficient of variation better than 5% (over four replicates). The value of beta allowed the calculation of the molar fraction of NaBD4, x(LIBS), with a coefficient of variation better than 2.5%. The comparison of x vs. x (LIBS) gives results that are in good agreement, within an average deviation of 3%, for x in the range of 50-100%. The best performances are obtained for beta close to unit, which makes LIBS perfectly suited for the detection of H-D exchange taking place during aqueous hydrolysis of NaBD4 or NaBH4. (c) 2006 Elsevier B.V. All rights reserved.