黑色圆珠笔的色谱法鉴定

发布时间：2018-11-11 18:13

【摘要】：随着计算机和网络的发展，电子通信，电子署名和整体电子经济业务变得越来越流行，但是以笔墨书写的文件依然是人们在商业交往中广泛使用和信任的法律文件。因此，可疑文件的检测依然是法庭科学中的重要课题。本文主要针对国内外不同生产厂家的33种黑色圆珠笔进行色谱法分类的研究，主要包括薄层色谱法(TLC)，，高效液相色谱法(HPLC)和气相色谱法(GC)。首先，本文概述了油墨的主要成分，包括染料，溶剂，树脂以及抗氧化剂，耐热剂以及防水剂和耐光剂等。并对TLC，HPLC以及GC在该领域的研究进行了总结。其次，通过薄层色谱法，高效液相色谱法以及气相色谱法对样品笔进行了系统的分析。其中，薄层色谱法由于具备操作方便，廉价以及快速等优点得到广泛应用。根据油墨中不同的化学组分在薄层色谱测定中产生的斑点的个数以及比移值的不同对圆珠笔进行分类。根据本实验的薄层色谱条件，将黑色圆珠笔分为12类。薄层色谱法分辨能力有其局限性，对于组分的微小的差异不能区分，由于高效液相色谱具有更高的灵敏度和分辨率，因此，研究了高效液相色谱法对这些圆珠笔进行测定的方法。该方法中，使用SunFire C-18色谱柱，以乙腈：水(NH_4HCO_3)=60：40(PH=8)做流动相，二极管阵列多波长检测器对200-700nm进行扫描。该方法大大提高了灵敏度和分辨率，同时用流程图根据不同波长下的色谱峰进行了再次分类，HPLC进一步区分了TLC不能区分的油墨。HPLC不能被广泛应用的原因主要是它要求取样量大，操作者需具有一定仪器操作的熟练程度以及耗资昂贵等局限性。气相色谱法主要用于分析油墨中的挥发性组分，本实验中，用气相色谱法对样品笔进行了分析，将其分为四大类。但是气相色谱法更多的用于鉴定油墨的书写时间而不是圆珠笔的分类。最后，用本文中建立的实验方法对北京市刑事技术研究所送检的盲测样品(6个黑色圆珠笔油墨字迹)进行测定，经送检者确证，实验结果与真实结果完全吻合。
[Abstract]:With the development of computer and network, electronic communication, electronic signature and the whole electronic economic business become more and more popular, but the documents written in pen and ink are still the legal documents widely used and trusted by people in business exchanges. Therefore, the detection of suspicious documents is still an important subject in forensic science. This paper focuses on the classification of 33 kinds of black ballpoint pens from different manufacturers at home and abroad, including thin layer chromatography (TLC), (TLC), high performance liquid chromatography (HPLC) and gas chromatography (GC). First of all, this paper summarizes the main components of ink, including dyes, solvents, resins and antioxidants, heat resistant agents and water-repellent and light resistance. The research of TLC,HPLC and GC in this field is summarized. Secondly, the sample pen was systematically analyzed by thin layer chromatography, high performance liquid chromatography and gas chromatography. TLC has been widely used because of its advantages of convenient operation, low cost and fast operation. The ball-point pen was classified according to the number of spots produced by TLC and the specific shift value of different chemical components in ink. According to the conditions of TLC, black ballpoint pens are classified into 12 categories. The resolution ability of TLC has its limitations, and the small differences in components can not be distinguished. Because of the higher sensitivity and resolution of HPLC, therefore, A method for the determination of these ballpoint pens by high performance liquid chromatography (HPLC) was studied. In this method, SunFire C-18 column was used, acetonitrile: water (NH_4HCO_3) = 60:40 (PH=8) was used as mobile phase, diode array multi-wavelength detector was used to scan 200-700nm. The sensitivity and resolution of the method are greatly improved, and the flow chart is used to reclassify the chromatographic peaks at different wavelengths. HPLC further distinguishes the inks that TLC can't distinguish. The main reason why HPLC can not be widely used is that it requires a large amount of sampling, the operator must have a certain degree of proficiency in the operation of the instrument, and the cost is expensive and so on. Gas chromatography is mainly used for the analysis of volatile components in ink. In this experiment, sample pens were analyzed by gas chromatography and divided into four categories. But gas chromatography is more used to identify ink writing times than ballpoint pen classification. Finally, the blind test samples (6 black ballpoint pen ink handwriting) submitted by Beijing Institute of Criminal Technology are determined by the experimental method established in this paper. The experimental results are in good agreement with the real results.
【学位授予单位】：首都师范大学
【学位级别】：硕士
【学位授予年份】：2006
【分类号】：D918.92

【参考文献】