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

从全球污染的角度来看，放射性核素~(99)和~(99)T_c已经引起了人们的极大兴趣。这种核素是最重要的裂变产物之一，因为它产生的裂变产额较高(6.06%)。由于其较长的半衰期(2.14×10~(-5)y)和几乎纯的β发射体的性质，其测定或检测不容易进行。本研究首次研究了激光诱导光声光谱(LPAS)方法在锶的测定中的应用。用氮气激光器泵浦染料激光器，获得合适的单色脉冲激光。自制了一种采用压电式换能器(PZT)作为信号检测器的检测部分。选择六(硫脲)锶(III)([TC(Tu)6]^&lt；3+&gt；)和六(异硫氰酸)锶(IV)([TC(NCS)6]^&lt；2-&gt；)配合物用于LPAS的测定。通过简单的化学处理，可以在合适的溶液中定量地得到这些配合物，它们在500 nm附近有强烈的吸收峰。对平均后的信号进行快速傅立叶变换(FFT)分析。定量观察了两种络合物在较宽的氚浓度范围内的FFT强度。对[TC(Tu)6]和[TC(Ncs)6]2-gt；分别可检测到10^-lt；-8&gt；M和10^&lt；-9&gt；M，比普通比色法的灵敏度高100-1000倍。

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.