红外光谱模式识别技术鉴定海洛因同一来源

本文应用红外光谱指纹图特征,通过研究模式识别检索的4种识别技术,考察对同一批次毒品的同一认定的置信度,从而筛选最佳鉴定方法.     

付立叶红外显微镜及其附件检验微量纤维

通过付立叶红外显微镜及其附件ATR、金刚石池对微量纤维进行检验,从而达到对微量或痕量纤维准确确定其种属和比对检验是否相同的目的,方法准确、快捷、可靠.     

应用FTIR光谱技术推断死亡时间

目的 应用傅立叶变换红外(FTIR)光谱技术分析大鼠死后组织、人体离体组织随死亡时间推移的化学降解过程,为死亡时间推断的研究提供新的途径与方法.方法 大鼠断颈处死后置于4℃、20℃、30℃环境,在不同死亡时间点提取大鼠不同组织;收集有同样死亡时间的人尸体组织,离体取材,并运用FFIR光谱仪测定不同化学基团随死后和离体后...     

Passport examination by polarized infrared spectra

In this study, a new nondestructive technique for passport examination is proposed. In this technique, linearly polarized light is used to measure Fourier transform infrared (FT-IR) reflectance spectra of films on the biographical data page. Thirty genuine and thirty-five counterfeit Japanese passports and five marketed films pasted on name cards were examined. The measured spectra were analyzed as follows. The absorption spectra were obtained by the Kramers-Kronig transformations of reflectance spectra. The peak ratios were then calculated from the absorption spectra by adding the peak areas at 1126 and 1263 cm(-1) and dividing the result by the peak area at 1727 cm(-1). When nonpolarized light was used, the samples could not be distinguished by comparing the peak ratios. However, when polarized light was used, they were successfully distinguished by the comparison. Therefore, polarized light is useful for the forensic discrimination of passport films by the measurement of FT-IR spectra.     

ATR技术鉴定二组分混纺纤维

利用红外衰减全反射光谱技术,检验腈-棉、毛-腈、棉-毛等常见二组分混纺纤维,可获得腈、棉、毛纤维的独立特征峰,其吸光度与纤维的含量之间,具有良好的线性关系.因此,根据ATR谱,不但可以准确鉴别混纺纤维的组成,而且可以准确测定纤维的混纺比.     

Analysis of thin-layer chromatograms of paint pigments and dyes by direct microspectrophotometry

The Nanospec 10S microspectrophotometer has been used to produce reflectance spectra over the 380–900 nm range from coloured thin-layer chromatography spots. The method has been applied to extracted paint pigments and to dyes from other materials examined in forensic science.     

优化AMDIS软件建库自动筛选常见有机毒物

目的优化AMDIS软件,建立常见有机毒物的GC/MS自动筛选方法。方法建立信息型中文常见毒物的质谱库,优化分离条件并测定多种毒物的保留时间,优化检索条件并测定多种毒物的检测限。结果建立含2344种常见药毒物的中文质谱库;测定了162种药毒物的保留时间及检测限。结论优化的AMDIS自动筛选常见药毒物,快速、灵敏、可靠,完全满足可疑含毒检材中毒物排查的要求。     

电烧伤皮肤金属元素的测定

本实验系用220V交流电源和直径2.0mm紫铜线为接触电极,在新鲜尸体腹部皮肤上做电烧伤实验。用原子吸收分光光度计对电烧伤皮肤中铜元素含量进行测定。结果表明电烧伤皮肤铜元素含量最高可达137.90μg/g。经10%福尔马林溶液固定40天以上的电烧伤皮肤铜元素含量有昕降低,但仍较正常皮肤含量为高。电烧伤皮肤铜元素含量以电流斑处为最高。本实验为电烧伤皮肤金属元素的定性与定量分析,检材的提取和处理,提供了一个较好的方法,有利于判定案件的性质和确定接触电极的金属种类。     

The Differentiation of Menstrual from Venous Blood and Other Body Fluids on Various Substrates Using ATR FT‐IR Spectroscopy

Crime scene investigators and laboratory analysts use chemical tests to detect and differentiate body fluids. Testing often requires a sample of the stain, and the chemicals may cause degradation of the fluid or interfere with subsequent tests. Colorimetric chemical tests do not differentiate between different types of the same fluid, such as venous and menstrual blood, and there is no presumptive test available to simultaneously differentiate several body fluids. In this study, we recorded ATR FT ‐IR spectra of venous and menstrual blood, semen, saliva, and breastmilk. Neat and simulated casework body fluid samples were analyzed on cotton, nylon, wood, paper, and glass substrates. Differences in fluid composition, including proteins and small molecules, resulted in spectral differences. Venous and menstrual blood is differentiated by the peak at 1039 cm^?1 attributed to phosphoric acid found in menstrual blood. Peak intensity is influenced by the porosity and weave of the substrate fabric.     

蓝色圆珠笔字迹色痕FT-IR光谱经时变化的研究

笔者曾用FT-IR光谱法对108种不同蓝色圆珠笔油墨进行了系统分析,确定了油墨组成成份,实现了种类认定.在此基础上,选取了二种不同种类的蓝色圆珠笔油墨字迹色痕,在紫外光下定时照射,根据各自光谱特征峰校正峰高的计算,确定相关峰的相对峰高比.根据相对峰高比值随时间变化的规律,进行了曲线拟合和计算机编程.同时,探讨了油墨组份之间随光照时间的变化,其目的是为了推断字迹色痕的“年龄”.