Determination of trace amount of Tc by laser induced photoacoustic spectroscopy.

从<99>全球污染的观点来看，放射性核素^ Tc引起了极大的兴趣。这种核素是最重要的裂变产物之一，因为它具有相对较高的裂变产额（6.06%）。由于其半衰期长（2.14 x 10^5 y）和几乎纯β发射体的特性，其测定或检测不容易进行。本研究首次探讨了激光诱导光声光谱（LPAS）方法在锝测定中的应用。用氮气激光器泵浦染料激光器，获得合适的单色脉冲激光束。自制了以压电陶瓷（PZT）为信号检测元件的检测部分。选择六硫脲锝（III）（[Tc（tu）6]^&lt;3+&gt;）和六异硫氰酸锝（IV）（[Tc（NCS）6]^<2->）配合物用于LPAS测量。这些配合物在适当的溶液中经简单的化学处理即可定量得到，在500 nm附近有较强的吸收峰。在取平均信号后进行快速傅立叶变换（FFT）分析。的FFT强度定量观察两种配合物的锝浓度的宽范围内。该检测可以分别进行到低至10 μ <-8>M的[Tc（tu）6]^&lt;3+&gt;和低至10 μ <-9>M的[Tc（NCS）6]^<2->，显示出比普通比色测量高100 - 1000倍的灵敏度。

The radioactive nuclides, ^<99>Tc, has been of great interest from the view-point of global pollution. This nuclide is one of the most important fission products, because it is produced with comparatively high fission yield (6.06%). Because of its long half life (2.14 x 10^5 y) and a character of almost pure beta-emitter, its determination or detection can not be easily performed. In this study, the application of Laser Induced Photoacoustic Spectroscopy (LPAS) method to the determination of technetium was examined for the first time. A nitrogen gas laser was used to pump up a dye laser to obtain suitable monochromatic pulsed laser beam. A detection part which involves piezo-electric transducer (PZT) as a signal detector was home-made. Hexakis(thiourea)technetium(III) ([Tc(tu)6]^<3+>) and hexakis(isothiocyanato)technetium(IV) ([Tc(NCS)6]^<2->) complexes were chosen for the LPAS measurements. These complexes can be quantitatively obtained in the appropriate solution with simple chemical treatment, and they show intense absorption peaks near 500 nm region. Fast Fourier Transform (FFT) analysis was conducted after taking averaged signals. The FFT intensity was quantitatively observed for the wide range of technetium concentration for both complexes. The detection could be performed down to 10^<-8> M for [Tc(tu)6]^<3+> and to 10^<-9> M for [Tc(NCS)6]^<2->, respectively, showing 100 - 1000 times more sensitive than the ordinary colorimetric measurement.