LASER ABLATION/SUPERSONIC BEAM/MULTIPHOTON IONIZATION/MASS SPECTROMETRY OF CHEMICAL SPECIES RESULTING FROM BIOLOGICAL AND SYNTHETIC POLYMERS

反射飞行时间质谱仪的质量分辨率大大提高，它很容易允许分配的含氯化合物。此外，通过将电离室的温度降低至液氮温度来降低背景信号。通过将光学参量振荡器的二次谐波发射与受激拉曼散射转换，真空紫外区的光谱测量成为可能。首先，我们比较了热分解和激光烧蚀方法制备超声射流光谱法样品的方法。我们发现，激光烧蚀技术提供了一个母离子更有效地和热分解技术的二聚体和三聚体离子。我们还将本技术应用于由用作包装材料的聚苯乙烯泡沫热分解形成的油，并发现含有各种化学物种，如苯乙烯，甲苯，苯等。（500 fs，248 nm）的热分解产物产生的合成（例如苯乙烯）和生物（例如腺嘌呤）聚合物，我们发现与使用纳秒脉冲的情况相比，母体分子更有效地形成。因此，短激光脉冲被发现是有用的测定分子量。为了将本方法应用于真实的样品，有必要开发一种方法来分配从光谱中观察到的信号峰的化学物种。我们构建了一个数据库，使用波长计允许光谱测量的精度为1/1000000。我们还提出了一种新的方法来指定的化学物种之间的标准和样品的光谱相似性。

The mass resolution of the reflectron time-of-flight mass spectrometer was greatly improved, and it readily allowed the assignment of the chlorine-containing compounds. Furthermore, the background signal was reduced by decreasing the temperature of the ionization chamber to a liquid nitrogen temperature. By converting second harmonic emission of the optical parametric oscillator with stimulated Raman scattering, spectrometric measurements in the vacuum ultraviolet region became possible.First, we compared thermal decomposition and laser ablation methods in preparatioin of the sample for supersonic jet spectrometry. We found that the laser ablation technique provides a parent ion more efficiently and the thermal decomposition technique dimer and trimer ions. We also applied the present technique to the oil formed by thermal decomposition of polystirene foam used as packing materials, and found to contain various chemical species such as stirene, toluene, benzene, etc. When we applied a femtosecond excimer laser pulse (500 fs, 248 nm) to thermally decomposed products resulting from synthetic (e.g.stirene) and biological (e.g.adenine) polymers, we found that parent molecules were more efficiently formed in comparison with the case using a nanosecond pulse. Therefore, a short laser pulse was found to be useful in determination of a molecular weight.In order to apply the present method to authentic samples, it is necessary to develop a method to assign chemical species from the signal peaks observed in the spectrum. We constructed a database using a wavemeter allowing the spectrometric measurements in an accuracy of 1/1000000. We also proposed a new method to assign the chemical species from the similarity of the spectra between the standard and the sample.