基于共焦显微拉曼光谱的蓝色圆珠笔墨迹的研究

Research of Blue Ballpoint Pen Inkblot Based on Confocal Micro-Raman Spectroscopy

利用514.5 nm可见光氩离子激光器作为激发光源,运用显微共焦拉曼光谱技术,测试了不同品牌蓝色圆珠笔墨迹的拉曼谱图。根据拉曼谱图的特征峰的峰强、峰位及走势,简单快速地识别了不同品牌蓝色圆珠笔的墨迹,且同一种品牌墨迹经选择多点测试后拉曼谱图保持了较好的一致性。对同一品牌圆珠笔墨迹进行时间跟踪测试,时间跨度为一年半,结果发现它的拉曼光谱呈现出了一定规律,这为墨迹形成时间的量化提供了依据。该实验结果为鉴定蓝色圆珠笔墨迹种类提供了法庭科学依据,对涂改,添加,伪造合同和文书中的内容及签名提供了强有力的证据,其最大优点就在于对样品的无损性,其次还有快速、无需对样品预处理和测试方法简单等。

The Raman spectra of different brands blue ballpoint pen ink marks were measured by confocal micro-Raman spectroscopic technique. The Raman spectra were excited with 514. 5 nm radiation. According to characteristic Raman bands, intensities and its trend, we can simply and quickly identify the ink marks of different brands blue ballpoint pen. Many points were chosen to be measured from the same brand blue ballpoint pen ink marks, and the Raman spectra keep consistency. For the same brand blue ballpoint pen ink marks, we track to measure their Raman spectra for a year and a half and it is found that Raman spectra of the same brand blue ballpoint pen ink marks made in different time have certain regularity with time going on. These lay the foundation for the quantification of the time. The results will offer scientific evidence for court to identify the types of ink marks and provide sufficient evidence for the commits such as altering the signatures in the contracts. The methods have the advantages such as high-speed, simplicity, no pretreatment, and particularly non-destructiveness.