A trial construction of a new instrument for a high sensitive determination on liquid surface.

(1)目的建立一种基于激光双光子电离技术的新型仪器，用于几纳米厚度液体表面的高灵敏度测定。还应将其应用于各种项目。(1)设计与施工。///通过购买单色仪、压电控制器和各种光学部件，设计并构建了一种新的仪器。该仪器旨在提高灵敏度和空间分辨率。(2)对构建的仪器进行评估。///通过改变溶液的表面压力和pH值，利用该仪器测量了芘衍生物的双光子电离信号。测定了这些化合物的pKa值，发现它们在溶液和表面上是不同的。测定了几种化合物在水面上的分析曲线。(3)适用于小范围内的高灵敏度测定。///我们尝试用微电极测量信号电流，灵敏地测定水和玻璃表面的几种芳香分子。蒽的检出限为12 fmol。(4)皮秒激光器的应用。///为了确定激光脉冲宽度的影响，我们尝试使用皮秒NdYAG激光器作为激发源。我们发现，当1064 nm的光束与3555 nm的光束重叠时，灵敏度增加。(5)激光诱导荧光技术的评价。///我们还在共聚焦荧光显微镜的基础上研制了一种新的仪器。测定了卟啉化合物的荧光光谱和分子分布，表明该仪器具有表面特异性。

(1) Purpose Based on the laser two-photon ionization technique, a new instrument should be constructed for high sensitive determination on liquid surface of a few nanometer thickness. Application to various projects should also be carried out.(2) Results(1) Design and construction. /// A new instrument was design and constructed with a purchase of a monochromator, a piezo controller and various optical parts. The instrument was aimed to improve sensitivity and spatial resolution compared to the previous one.(2) Evaluation of the constructed instrument. /// The two-photon ionization signals of pyrene derivatives were measured using the new instrument by varying the surface pressure and pH of the solution. The value of pKa of these compounds were determined and found to be different in solution and on surface. The analytical curves of several compounds on water surface were also determined.(3) Application to high sensitive determination in a very small region. /// We have tried to determine several aromatic molecules on surface of water and glass sensitively using a micro electrode to measure the signal currents. The detection limit of anthracene was 12 fmol.(4) Application of a pico-second laser. /// In order to determine effects of the laser pulse width, we tried to use a pico-second NdYAG laser for an excitation source. We have found that the sensitivity increased when the 1064 nm beam was overlapped with the 355 nm beam.(5) Evaluation of the laser-induced fluorescence technique. /// We have also constructed a new instrument based on the confocal fluorescence microscope. The fluorescence spectrum and molecular distribution of porphyn compounds have been determined to indicated the new instrument is surface specific.