墨水老化方法的研究

发布时间：2018-02-28 19:25

本文关键词： 墨水老化高效液相色谱气相色谱书写时间文件检验　出处：《首都师范大学》2006年硕士论文　论文类型：学位论文

【摘要】：在如今的社会刑事案件中常常会涉及到很多可疑文件，需要对其使用的墨水的书写时间进行鉴定从而判断文件的真伪。自从1950以来，世界各国的法庭科学工作者经过不懈的探索，陆续的建立了一些方法用于实际办案，其中有些鉴定结论已被一些国家的司法部门所接受。但是，由于油墨组成成分的复杂性和测定的干扰性，可疑文件与墨水书写时间的鉴定仍然是当前法庭科学的难题之一，因而可疑文件与书写时间的鉴定有重要的意义。本论文分五部分进行研究。第一章介绍了油墨的主要成分，综述了近年来国内外关于墨水书写时间鉴定的发展与应用，主要是关于墨水老化部分的综述，包括相对老化和加速老化。第二章利用气相色谱法测定蓝色圆珠笔油墨中展色剂苯甲醇和苯氧基乙醇这两种组分的含量(以峰面积计)，以展色剂的峰面积、内标物的峰面积与紫外可见光谱测得的参比物墨水中的染料的吸光度值这三者之比为纵坐标，以字迹形成时间为横坐标，确定了字迹形成曲线，从而建立了确定字迹形成时间的方法。选择了不同种类的圆珠笔油墨进行检测，获得了良好的实验效果，，为圆珠笔油墨字迹形成时间的推断建立了一种可靠而又系统的方法。据此方法可以鉴别书写时间在半年以内的墨水字迹。系统研究了选择适当的内标物。第三章研究了紫外分光光度法确定兰黑钢笔墨水书写时间，选取了适当的提取剂和络合剂，选择铁作为内参比物，用染料的吸光度与墨水中铁的比值与老化时间绘制了老化曲线，据此可以鉴别书写6个月左右的钢笔墨水字迹。第四章研究了双溶剂萃取法鉴别圆珠笔油墨书写时间，实验选取了强溶剂和弱溶剂，并且分别用薄层色谱法、紫外分光光度法和电化学法对相同的样品进行了测定，得出了相同的结论，据此得出此方法有很好的稳定性。第五章通过高效液相色谱法，研究了染料成分的变化，从而确定字迹形成相对时间，将纯染料字迹和圆珠笔油墨字迹放在强光照射、红外、紫外、加热和室内自然光等条件下，然后再从纸上提取用HPLC分析，发现光的照射下染料和墨水的成分变化很大，根据老化后染料成分及含量的变化可以鉴别圆珠笔油墨的书写时间。
[Abstract]:In today's social criminal cases, many suspicious documents are often involved, and it is necessary to identify the writing time of the ink used to determine the authenticity of the documents. After unremitting exploration, court scientists from all over the world have successively established some methods for the practical handling of cases, some of which have been accepted by the judicial authorities of some countries. However, Due to the complexity of the composition of the ink and the interference of the determination, the identification of the writing time of the suspected documents and ink is still one of the difficult problems of the current forensic science. Therefore, the identification of suspicious documents and writing time is of great significance. This paper is divided into five parts. The first chapter introduces the main components of ink, and summarizes the development and application of ink writing time identification at home and abroad in recent years, mainly about the aging part of ink, including relative aging and accelerated aging. The second chapter uses gas chromatography to determine the content of benzyl alcohol and phenoxy ethanol in blue ballpoint pen ink. The ratio of the peak area of the internal standard and the absorbance value of the dye in the reference ink measured by UV-Vis spectrum is the vertical coordinate, and the writing forming curve is determined with the writing forming time as the horizontal coordinate. Thus, the method of determining the time of writing formation was established. Different kinds of ballpoint pen ink were selected for detection, and good experimental results were obtained. A reliable and systematic method for estimating the time of ink writing in ballpoint pen is established, according to which the ink handwriting with writing time less than half a year can be identified. The selection of appropriate internal standard materials is studied systematically. The third chapter studies the determination of the writing time of blue and black pen ink by ultraviolet spectrophotometry. The proper extractant and complexing agent are selected, and iron is chosen as the internal reference material. According to the ratio of dye absorbance to iron in ink and aging time, the ageing curve can be drawn, according to which the ink handwriting of about 6 months can be identified. In chapter 4th, double solvent extraction method was used to identify the writing time of ballpoint pen ink. Strong solvent and weak solvent were selected, and the same samples were determined by thin-layer chromatography, ultraviolet spectrophotometry and electrochemical method, respectively. The same conclusion is obtained, and it is concluded that the method has good stability. In Chapter 5th, the changes of dye composition were studied by HPLC, and the relative time of writing formation was determined. The pure dye handwriting and ballpoint pen ink handwriting were placed under the conditions of strong light irradiation, infrared, ultraviolet, heating and indoor natural light. Then the paper was extracted by HPLC analysis. It was found that the composition of dye and ink changed greatly under the irradiation of light. According to the change of composition and content of dye after aging, the writing time of ink of ballpoint pen could be identified.
【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

【引证文献】