Development of a new method for the analysis of individual biological history of the aquatic creatures using synchrotron radiation X-ray fluorescence imaging

经过三年的调查，得到了以下结果：样品制备：建立了同步辐射x射线荧光微探针分析的样品制备方法。对于鱼耳石制备，建议采用30mm厚的耳石核矢状面进行分析。2 .指纹元素的研究：对不同来源鱼类的耳石进行ICP-AES分析，发现其微量成分中含有Sr、Zn、Fe、Mg、Mn和Al，其中Sr最适合作为其所处环境水体盐度变化的指示物。同步辐射的应用：利用同步辐射x射线荧光微探针澄清了Ca、Sr和Fe的二维分布。测量是在光子工厂，高能加速器研究组织。样品由Si（111）双晶单色器产生的17kev x射线激发。利用x射线微光束，在光束尺寸约为100 × 100 μ m / 2，计数时间为10秒/步的条件下，成功地进行了铁等微量元素（平均约为100 ppm）的二维分析。因此，我们建立了XRF成像技术作为表征耳石中微量元素的一种新的重要工具。仪器：我们开发了一种新的x射线荧光成像系统，用于常规实验室x射线源对硬组织中的微量元素进行常规分析。该系统利用由弯曲石墨单色仪获得的单色Mo Ka x射线，使我们能够进行高灵敏度分析。方法的验证：为了验证这里开发的方法，对淡水鳗鱼、马苏鲑鱼和灯笼鱼的耳石进行了分析。结果表明，个体的迁徙历史得到了很好的展示，因此我们认为这种方法得到了充分的验证。

After the investigation for three years, the following results have been obtained.1.Sample Preparation : Methods of sample preparation for synchrotron radiation X-ray fluorescence microprobe analysis was developed. For the fish otolith preparation, sagaital plane with otolith core of 30mum thick was revealed to be suitable for the analysis.2.Investigation of finger-print elements : ICP-AES analysis of otoliths of various fishes of different origin disclosed that they contain Sr, Zn, Fe, Mg, Mn and Al as trace components, among which Sr is found to be most suitable for the indicator of the salinity change of their environmental water.3.Application of Synchrotron Radiation : Two-dimensional distributions of Ca, Sr and Fe were clarified by synchrotron radiation X-ray fluorescence microprobe. Measurements were made at Photon Factory, High Energy Accelerator Research Organization. Samples were excited by an X-ray of 17 keV generated by a Si (111) double-crystal monochromator. Two dimensional analysis of trace elemenls such as iron (average : around 100 ppm) was successfully carried out by using X-ray microbeam under the following condition : beam size, ca 100x1OO um2 and counting time of 10sec/step. Thus we have established the XRF imaging technique as a new important tool for characterization of the trace elements in the otoliths.4.Instrumentation : We have developed a new X-ray fluorescence imaging system for routine analysis of the trace elements in the hard tissues by using conventional laboratory X-ray source. This system utilizes monochromatic Mo Ka X-ray obtained by a curved Graphite monochoromator, which enables us to carry out high sensitivity analysis.5.Validation of the methods : To verify the method developed here, otoliths of the freshwater eel, masu salmon and lantern fish were analyzed. As the results, the individual migratory history was well demonstrated and thus, we conclude this method was sufficiently verified.