高效液相色谱法分析蓝色的圆珠笔油墨中染料

采用反相高效液相色谱法-二极管阵列检测器对88种不同产地、不同厂商、不同品牌的蓝色的圆珠笔油墨字迹进行分析。以Xterra MS C18柱(3.9 mm×150 mm,5μm)为分离柱,0.01 mol.L-1碳酸氢铵溶液与乙腈以体积比35比65混合溶液为流动相,流量为0.8 mL.min-1。根据油墨中分离出的主要染料成分结晶紫、甲基紫、碱性品蓝、碱性艳蓝B、碱性艳蓝BO、磺化铜酞菁、罗丹明B含量的不同,将所被分析的圆珠笔分为9类,并提出了根据染料成分的相对峰面积来区分同类圆珠笔品牌的方法。     

非水毛细管电泳法区分蓝色圆珠笔油墨的研究

建立了一种基于非水毛细管电泳法区分蓝色圆珠笔油墨的方法.确定了笔迹中碱性染料(结晶紫、甲基紫、碱性品蓝、罗丹明6G、碱性艳蓝B和碱性艳蓝BO)的分离条件:缓冲溶液为1.00 mmol/L醋酸-100 mmol/L醋酸铵的甲醇-水(体积比90 ∶ 10)体系,分离电压和温度分别为25 kV和25 ℃,检测波长为214 nm.通过该方法分析了96支蓝色圆珠笔中的油墨,并依据油墨中所含的染料种类对圆珠笔进行分类,同一类笔又通过聚类分析计量学方法再次进行区分.该法重复性好,结果准确可靠,为圆珠笔字迹鉴定提供了一种科学的方法.     

用气相色谱-质谱法和薄层色谱法分析蓝色圆珠笔油墨及其分类

采用气相色谱-质谱法和薄层色谱法对110支不同产地、品牌的蓝色圆珠笔油墨进行检测及种类鉴定。以气相色谱-质谱法研究了圆珠笔油墨中的溶剂组成,据此样品可分为6大类;以薄层色谱法检测了油墨中的染料组成,根据染料斑点的个数、位置、颜色及薄层扫描后吸收峰中标准峰的位置,将样品分为了17类。综合分析上述两种色谱检测的结果,同时考察溶剂和染料在组成上的差异,将110支不同品牌、产地的蓝色圆珠笔分为了35类,可以达到某些品牌之间的区分和认定,比依据单一检验手段得到的分类结果更为精准、系统。     

基于多变量-系统聚类分析法区分蓝色圆珠笔色痕

综合应用不同的检验方法对110支不同产地、品牌的蓝色圆珠笔油墨进行检验及种类鉴定。采用气相色谱-质谱法和薄层色谱法分别研究了圆珠笔油墨中的溶剂组成和染料组成。通过数据预处理,分别建立了不同样品气相色谱法和薄层色谱法的共有谱图,采用二值法对特征数据进行提取,将定性信息数量化,将欧氏距离的平方作为样品之间差异的量度进行系统聚类分析,并将分类结果用于判别分析,建立相应的判别式函数。结果表明,基于多变量的系统聚类结果由于同时考察油墨的溶剂和染料在组成上的差异,将110支不同品牌、产地的蓝色圆珠笔分为了29类,可以达到品牌之间的区分和认定,较依据单一检验手段得到的分类结果更为精确、系统。尝试结合判别式函数对未知色痕进行分类,由于样本量较少,因此交叉验证得到的分类正确率仅为47.7%,但通过本实验将化学计量学中的相关算法引入到油墨种类的鉴别中,为添改文件、文件形成时间的检验提供了更加准确的结果,为建立油墨样本库提供了数据支持。     

圆珠笔油墨字迹色痕的高效液相色谱分析方法

采用正交实验设计法从多种流动相体系中优选出了圆珠笔油墨字迹色痕的高效液相色谱分析条件。在此条件下分析了105种市售的不同生产厂家和牌号蓝色圆珠笔油墨的字迹色痕,并依据有色成分的差异将这些同色油墨分成了6大类,考察了纸张的影响因素及在该条件下分析结果的重现性和精密度,为进一步分析鉴定圆珠笔字迹色痕的形成时间提供了有利条件。     

黑色圆珠笔油墨的高效液相色谱法分析

建立了黑色圆珠笔油墨字迹色痕的高效液相色谱法的分析条件和实验方法,采用乙腈-NH4HCO3溶液（10mmoL／L）（体积60：40）为流动相,检测波长580nm,同时利用质谱法作为佐证。在此条件下对市售的51支不同生产厂家和品牌黑色圆珠笔油墨的字迹色痕进行了分析,根据油墨中所含染料成分的差异将其分为6大类,考察了纸张的影响及在该分析条件下结果的精密度和重复性。     

气相色谱法确定蓝色圆珠笔油墨字迹的形成时间

选择适当的内标物,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。选择了不同种类的蓝色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。该方法适用于实际办案。     

离子对反相薄层色谱法分离三苯甲烷碱性染料

1 引言 三苯甲烷碱性染料是一类水溶性的阳离子染料。由于它们的分子结构非常相似,分离比较困难。本文用自制的GDX和硅胶G混合物制成的薄层板,采用离子对反相技术,分离了结晶紫、甲基紫、乙基紫、碘绿和孔雀石绿等五种三苯甲烷碱性染料,得到满意结果,方法简单、快速,对这类染料的鉴别和纯度分析都具有实用     

傅里叶变换红外光谱无损识别蓝色圆珠笔油墨染料组分

１　引　言 在刑事案件、民事案件、经济案件的侦察诉讼中以及纪检、监察、公诉、仲裁等活动中,有许多与案件有关,怀疑被同色墨水篡改的文件需进行司法鉴定。因此,对油墨组成及笔迹的鉴定就显得非常重要,圆珠笔油墨主要由染料、树脂、溶剂润滑剂组成,蓝色笔油中的染料主要有铜钛青和三芳甲烷两种。染料的不同配比将引起红外光谱的峰位置、峰形、峰强发生变化,由此可识别混合谱中染料的种类及配比,这为进一步利用红外光谱对蓝色圆珠笔笔迹形成时间的原位识别的深入研究打下了良好的基础。２　实验部分２．１　仪器设备及参数　美国Ｐ…     

加压毛细管电色谱法在鉴别圆珠笔油墨中的应用

采用加压毛细管电色谱法对不同圆珠笔油墨样品进行分析。实验结果表明,不同样品在成分及含量上有较大的差别,可作为检验和比对圆珠笔油墨种类的参考依据。该方法的精密度及重复性良好,可为刑事侦查领域中笔迹检验及油墨鉴别提供一个全新的方法。     

Determining the relative age of blue ballpoint ink by gas chromatography

A method for identifying the writing age of blue ballpoint pen ink has been established due to the imperative demand in forensic laboratories. The content of the volatile components in blue ballpoint pen ink were determined by gas chromatography (GC). The absorbance of dye in blue ballpoint pen ink was measured by UV-Vis spectrometry A writing age curve of the ink was established using the ratio of the content of the volatile components to the dye, based on the identification of 74 kinds of blue ballpoint pen ink of domestic and international origins. The change of benzene alcohol or phenoxetol with the writing age was also tested. Different kinds of blue ballpoint pen ink were detected and the repeatability of the experiment was investigated. The results indicate that the method is reliable, sensitive, systematic and is especially suitable for practical use. __________ Translated from Chinese Journal of Chromatography, 2005 (3)(in Chinese)     

Forensic classification of ballpoint pen inks using high performance liquid chromatography and infrared spectroscopy with principal components analysis and linear discriminant analysis

Several varieties of blue ballpoint pen inks were analyzed by high performance liquid chromatography (HPLC) and infrared spectroscopy (IR). The chromatographic data extracted at four wavelengths (254, 279, 370 and 400 nm) was analyzed individually and at a combination of these wavelengths by the soft independent modeling of class analogies (SIMCA) technique using principal components analysis (PCA) to estimate the separation between the pen samples. Linear discriminant analysis (LDA) measured the probability with which an observation could be assigned to a pen class. The best resolution was obtained by HPLC using data from all four wavelengths together, differentiating 96.4% pen pairs successfully using PCA and 97.9% pen samples by LDA. PCA separated 60.7% of the pen pairs and LDA provided a correct classification of 62.5% of the pens analyzed by IR. The results of this study indicate that HPLC coupled with chemometrics provided a better discrimination of ballpoint pen inks compared to IR. The need to develop a suitable IR method for analysing blue ballpoint pen inks has been emphasized and it is hoped that the development of such a method would indeed provide a valuable tool for the non-destructive analysis of blue ballpoint pen ink samples for forensic purposes.     

Nondestructive classification and identification of ballpoint pen inks by Raman spectroscopy for forensic document examinations

As a non-destructive analytical method, Raman spectroscopy often provides insufficient information to identify or differentiate the ink used for the preparation of a questioned document. In this study, blue and black ballpoint pen inks deposited on paper substrate were examined in situ by conventional Raman spectroscopy. Inks were successfully classified based on the total number of prominent bands in Raman spectra. It was found that more than 90% of the samples of the same type and color could be differentiated visually using only Raman spectra, i.e. 94 and 95% for blue and black inks, respectively. As a result of this study, a flow chart has been constructed for blue and black ballpoint pen inks allowing their systematic identification. Raman spectroscopy proved to be a fast and precise technique for forensic ink analysis.     

Photofading of ballpoint dyes studied on paper by LDI and MALDI MS

The determination of the age of an ink entry from a questioned document is often a major problem and a controversial issue in forensic sciences. Therefore, it is important to understand the aging process of the different components found in ink. The aim of this work is to characterize the degradation processes of methyl violet and ethyl violet, two typical ballpoint dyes by using laser desorption/ionization (LDI) and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS), and to evaluate the possible application of the method to forensic examination of documents. The mass spectrometric methods were first tested and were found to be adequate for the purpose of this work. Moreover, it is possible to analyze the dye from a stroke directly from the paper (LDI-MS), so the sample preparation is minimized. The degradation of the dyes methyl violet and ethyl violet in strokes from a ballpoint pen was studied under laboratory conditions influenced by different factors such as light, wavelength of light, heat, and humidity. Then, strokes from the same ballpoint were aged naturally in the dark or under the influence of light over one year and then analyzed. The results show that the degradation of these dyes strongly depends on light fluence. Humidity also increases degradation, which can be explained by the basicity of the paper. The influence of heat on the degradation process was found to be rather weak. It was also observed that the dyes from the ink strokes did not show significant degradation after one year of storage in the dark. In conclusion, the storage conditions of a questioned document and the initial composition of the dyes in the ink have to be known for correct interpretation of the age of an ink entry. Measurements over longer periods of time are necessary to follow the degradation of dyes exempt from light exposure. LDI was found adequate and very useful for the analysis of ballpoint dyes directly from paper without further pretreatment.     

Forensic Identification of Dyes in Ballpoint Pen Inks Using LC–ESI–MS

The aim of this work was to develop a new technique using flow injection analysis combined with LC–ESI–MS which allows identification of dyes in ballpoint pen inks. A sample preparation procedure for the extraction of dyes from ballpoint pen strokes has been developed. The characteristic group of ions for each sample of 21 studied ballpoint pen inks corresponding to the present dyes has been determined using flow injection method. LC separation conditions for identified dyes have been optimized on reversed-phase sorbent based on silica gel. The best composition of the mobile phase for the dyes mixture LC separation was 0.1% aqueous formic acid and acetonitrile. Detection of dyes was carried out using mass spectrometry with electrospray ionization in positive and negative modes after reversed-phase liquid chromatography separation. Dye composition of ink was additionally confirmed comparing the data obtained from the literature. Flow injection analysis allows obtaining intensive ions of unknown strokes. It is difficult to get this information using only chromatographic methods, because dyes peak intensity can be low and noise of basic line high. Flow injection method allows distinguishing the analyzed 21 ballpoint pens by determining a characteristic set of dyes. The developed flow injection technique is very simple and quick. As a result, a novel approach for the identification of dyes in the ballpoint pen inks by flow injection analysis with LC–ESI–MS and UV detection without using standard dye samples has been established. It can be an effective alternative to the existing LC–DAD–MS and IR spectroscopy methods.     

DATINK pilot study: An effective methodology for ballpoint pen ink dating in questioned documents

Establishing the approximate age of an ink entry from a questioned document is often a complicated task and a controversial issue in forensic sciences. Among the existing approaches, the analysis of solvents in ballpoint inks may be a useful parameter for determining the age of ink on paper. In recent years, several ink dating methods have been proposed. These methods have been based on the analysis of common ink solvents using gas chromatography/mass spectrometry (GC/MS) as the analytical platform. Despite these recent methods, several questions remain. The aim of this work was to develop an ink dating methodology (DATINK) for documents written by ballpoint pens based on the disappearance of volatile solvents from the ink entry. Multiple solid-phase microextraction (MHS-SPME) coupled to GC/MS was used to measure the solvents from ink entries made with four BIC^® ballpoint pens. The β parameter, the remaining fraction of the analyte in the system after one equilibration, corresponding to the successive extractions was considered for modelling a mathematical equation for later ink age dating. Preliminary tests of DATINK method showed that it was possible to detect the presence of ink solvents on documents up to the studied five years. The analyses of different real samples of known age were analyzed in terms of β values, which provided a mean relative error of 21%. The proposed use of β parameter for estimating the absolute age of ballpoint ink entries has shown promising results with a standard deviation of β ranging from 0.002 to 0.004.     

裂解气相色谱法分析蓝色中性笔字迹的书写墨水种类及墨迹随书写时间的变化规律

中性笔是当前比较流行的一种书写工具,其墨水多采用颜料作为色料成分,很难用水和有机溶剂进行提取,故无法利用分析圆珠笔油墨和水性笔墨水所采用的气相色谱或高效液相色谱等方法进行检验。目前在法庭科学领域内还没有一种有效的方法用于分析中性笔字迹的书写墨水。采用裂解气相色谱法分析了蓝色中性笔字迹的书写墨水,根据色谱峰的个数和保留时间将收集的65个样品分成3类,其中大部分样品属于具有铜酞菁颜料主要色谱峰的第二大类。色谱峰的保留时间和峰面积比值的分析结果表明所建立的分析方法重现性好且稳定。在此基础上,对蓝色中性笔墨迹随书写时间的变化规律进行了初步研究,得出了老化曲线。     

Studies on inclusion complexes of 2,4-dinitrophenol, 2,4-dinitroaniline, 2,6-dinitroaniline and 2,4-dinitrobenzoic acid incorporated with β-cyclodextrin used for a novel UV absorber for ballpoint pen ink

The inclusion complexes of β-cyclodextrin with different dinitrocompounds like 2,4-dinitrophenol, 2,4-dinitroaniline, 2,6-dinitroaniline and 2,4-dinitrobenzoic acid appears the UV absorption bands in different wavelength region below 400 nm, a combination of these dinitro aromatic compounds of inclusion complexes can improve the UV protection properties of ball point pen ink against photo degradation. The formation of inclusion complexes were characterized by FT-IR, ¹H NMR and 2D ROESY NMR spectroscopy. The UV protecting properties of these inclusion complexes were calculated their sun protection factor was discussed. The stability of the ballpoint pen ink has been confirmed by UV–visible spectroscopic method.     

显微共聚焦拉曼光谱结合群分析的黑色直液笔墨迹鉴别研究

黑色直液笔是一种新型书写工具,目前对该种笔墨迹的相关研究较少。为给文件检验工作中墨迹的分析提供新的参考依据,本实验使用显微共聚焦拉曼光谱技术,采集了30支不同品牌、型号的黑色直液笔墨迹光谱数据,进行Savitzky-Golay卷积平滑处理后,依据光谱图的拉曼位移及拉曼谱峰差异对墨迹进行初步分析。设置聚类方法为组间联接,区间距离测量方式为平方欧式距离,对采集的光谱数据进行群分析,将30支黑色直液笔墨迹样本分成了3类,并与品牌建立了相关联系;同时通过主成分分析验证了群分析的可靠性和准确性。研究表明,显微共聚焦拉曼光谱技术结合群分析方法可实现对黑色直液笔墨迹的无损分析及有效鉴别,该方法操作简便、结果准确,适用于法庭科学文件检验。