1. 中山大学化学与化学工程学院，广东 广州 510275 2. Institute of Spectrochemistry and Applied Spectroscopy (ISAS), Dortmund 44139, Germany
Measurement of Uranium Isotope Ratio in Solid Sample by Laser Ablation and Double-Beam Diode Laser Atomic Absorption
LIU Hong-tao1，ZHANG Zhan-xia1，Quentmeier A2，Niemax K2
1. Chemistry and Chemical Engineering College, Zhongshan University, Guangzhou 510275, China 2. Institute of Spectrochemistry and Applied Spectroscopy, Dortmund 44139，Germany
Abstract：The 235U／238U isotope ratio was determined by diode laser atomic absorption spectrometry in a plasma induced by a Nd:YAG laser. Two diode lasers, which probed almost the same plasma volume, were used as light sources. 235U and 238U absorption signals were simultaneously measured by tuning the diode lasers to the absorption lines 682.673 6 nm and 682.076 8 nm, respectively. The optimal focus position for the Nd:YAG laser was found to be 0.4 cm below the sample surface. The precision and accuracy of 235U／238U isotope ratio determination were obtained to be 5% and 2%, respectively. The detection limit of the 235U isotope, evaluated on the basis of 3σ criteria, was estimated to be 18 μｇ·ｇ-1. All these results show an improvement compared with the method in which only one diode laser was used as a light source.
Key words：Laser ablation;Diode laser;Atomic absorption spectrometry;Uranium;Isotope ratio
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