摘要钢笔墨水墨迹在公安工作中的案件一直较为常见,而其检验也是检验鉴定工作中的热点问题。为寻求一种高灵敏度、简便、快捷的钢笔墨水墨迹的检验方法对常见钢笔墨水进行种类区分,对几种较为常见的检验方法进行了论述,并对其优劣进行比较后选择了气相色谱-质谱联用法对9种不同品牌、型号样品进行检验。本实验采用乙腈液液萃取后,使用改进QuEChERS方法对样品进行净化。在气相色谱分离样品成分中使用RTX-5MS色谱柱,使用搜索特征离子的方法定性样品中含有的成分。本实验讨论了液液萃取溶剂、浓缩方式、净化方式的选择,优化了净化条件。结果显示不同品牌、型号的钢笔墨水间存在一定差异,并以差异性较强的10种有机化合物为检测目标物对9种样品进行分析,初步探究出钢笔墨水的成分差别,为公安工作提供一定理论帮助。78482
毕业论文关键词:气相色谱-质谱联用法;钢笔墨水墨迹;QuEChERS方法;液液萃取
ABSTRACT Pen ink is a common case in the public security work, and its inspection is also a hot issue in the inspection and appraisal work。 In order to find a high sensitivity, simple, fast and low-cost inspection method for pen ink, several common inspection methods are discussed, and their advantages and disadvantages are compared。 In this experiment, nine kinds of pen ink of different brands and models were extracted by acetonitrile, and the samples were purified by the improved QuEChERS method。 Rtx-5ms column was used in the separation of sample components by gas chromatography, and the components detected in the sample were identified by searching for characteristic ions。 At the same time, the solvent of liquid-liquid extraction, the way of concentration and the purification conditions were discussed。 The results show that there are some differences among different brands and models of pen ink, and 9 samples are analyzed with 10 detected organic compounds with strong differences。 The differences in composition of pen ink are preliminarily explored, which provides some theoretical help for public security work。
Keywords:GC-MS;Pen ink;QuEChERS method;liquid-liquid extraction
目 录
引 言 1
一、研究背景 1
(一)钢笔墨水墨迹的检验方法 1
1.薄层色谱法(TLC) 1
2.高效液相色谱法(HPLC) 1
3.毛细管电分离法(CESM) 2
4.气相色谱-质谱联用法(GC-MS) 2
5.各检验方法的优劣对比 2
(二)钢笔墨水墨迹的检验意义 3
二、实验部分 3
(一)样品、仪器与试剂 3
1.实验仪器 3
2.实验试剂 3
3.实验样品 3
(三)实验步骤 4
1.实验条件 4
2.具体步骤 4
三、讨论 5
(一)液液萃取溶剂的选择 5
(二)氮吹温度的优化 5
(三)净化条件的选择 6
(四)钢笔墨水墨迹的分析 6