高效液相色谱法分析黑色签字笔墨迹的种类和形成时间

The analysis of the extracts from black water-based pen ink by high performance liquid chromatography

对用反相离子对色谱法鉴定黑色签字笔墨迹种类及形成时间的研究进行了探讨。实验中,分析黑色签字笔墨迹中有色成分的流动相为V(甲醇)∶V(水)=60∶40含四丁基氢氧化铵、检测波长为580 nm。并对49种不同产地、不同牌号的黑色签字笔墨迹进行了种类分析。依据色谱图中色谱峰的数目、保留时间、峰形等数据,将其分为8大类。在此基础上,分析了黑色签字笔墨迹中各种染料成分相对含量随形成时间的变化规律。结果表明,反相离子对色谱法是一种鉴定黑色签字笔墨迹种类及形成时间异同的简便方法。

As it is a problem that we meet frequently in the laboratory of forensic science nowadays to distinguish whether the questioned documents, such as deeds, contracts, and receipts, written in black water-based pen ink are true or not and identify the writing age of them, it is very essential to establish a simple, sensitive and accurate method to examine the similarities and differences of the extracts from black water-based pen ink and identify the writing age. In this paper, the research on distinguishing the kind of the extracts from black water-based pen ink by reversed-phase ion-pair chromatography has been initially explore. In this research, the mobile phase for the analysis of the extracts from black water-based pen ink is methanol and water （60：40） containing tetrabutyl ammonium hydroxide. Detection wavelength is 580 nm. Under this condition, 49 kinds of extracts from black water-based pen ink from different places of production and with different brands were analyzed. According to the number of peaks in the chromatograrn, the retention time of the peaks and the spikes, they can be divided into 8 categories. The rules of the changes of the ratio of the areas or the heights of the peaks along time determine the writing age of black water-based pen inks. The results of the experiments show that the method mentioned is a simple, sensitive and accurate to examine the similarities and differences of the extracts from black water-based pen ink.