A target glitter study.

A target study was conducted using four different pre-selected types of commercial glitter particles. Recipient areas in the general environment around San Diego, California were tested. Glitter particles were recovered using double-sided tape affixed to square plastic Petri dishes. White light microscopy was the only search/identification method used. Additionally, a test was performed of the transferability of cosmetic glitter. Glitter particles were found to readily transfer. Of a total of 48 tape lifts from the general environment, 23 were found to contain at least one glitter particle. But due to the wide variety of glitter particles in terms of colour, shape, size, and surface morphology, the likelihood of transfer of one or more specific target particles was small.     

Analyzing Forensic Evidence Based on Density with Magnetic Levitation

This paper describes a method for determining the density of contact trace objects with magnetic levitation (MagLev). MagLev measurements accurately determine the density (±0.0002 g/cm³) of a diamagnetic object and are compatible with objects that are nonuniform in shape and size. The MagLev device (composed of two permanent magnets with like poles facing) and the method described provide a means of accurately determining the density of trace objects. This method is inexpensive, rapid, and verifiable and provides numerical values—independent of the specific apparatus or analyst—that correspond to the absolute density of the sample that may be entered into a searchable database. We discuss the feasibility of MagLev as a possible means of characterizing forensic‐related evidence and demonstrate the ability of MagLev to (i) determine the density of samples of glitter and gunpowder, (ii) separate glitter particles of different densities, and (iii) determine the density of a glitter sample that was removed from a complex sample matrix.     

Differentiation of Twenty‐One Glitter Lip‐Glosses by Pyrolysis Gas Chromatography/Mass Spectroscopy*

Abstract: Differentiation of 21 glitter lip‐glosses from seven manufacturers was attempted by pyrolysis gas chromatography/mass spectroscopy. Samples were pyrolyzed on a ribbon probe at 800°C for 20 sec and analyzed with an Agilent^® 6890N Network GC System and Agilent^® 5973 Network Mass Selective Detector with MSD Productivity ChemStation^® Data Analysis software. The total ion chromatograms obtained were examined and differences in the presence or absence of certain chromatographic peaks corresponding to certain pyrolysis products (e.g., styrene, cyclohexane) noted. In cases where the total ion chromatograms between lip‐glosses were similar, select ion profiling was performed. Of the 21 lip‐glosses, 15 were differentiated by either the total ion chromatograms alone or through select ion profiling. Considering that lip‐glosses are typically worn by young women (who are disproportionately victims of sexual assault), this study offers the potential of being able to provide investigative leads in sexual assault investigations with evidentiary samples of this kind.     

Variation of the amide I and amide II peak absorbance ratio in human hair as measured by Fourier transform infrared spectroscopy

Human scalp hair samples were examined by Fourier transform infrared spectroscopy and the ratio of the amide I to amide II band absorbances was determined. The effects of hair oxidation, color, age of sample, and sex of source were examined. Scalp hair from 98 individuals was also analyzed. While there were differences in the amide absorption band ratios, these were difficult to relate to the individualization of the hair samples and did not appear to have a sufficient discriminatory value for routine forensic use.     

A quantitative differentiation method for plastic bags by infrared spectroscopy, thickness measurement and differential scanning calorimetry for tracing the source of illegal drugs

Fifty shopping bags, commonly encountered in the packaging of drug doses, were characterized by thickness measurements, infrared spectroscopy and differential scanning calorimetry. By these very straightforward and inexpensive techniques, without sample preparation, nearly all the considered samples could be discriminated. Ninety-seven percent of the possible pairs of white, apparently similar dull polymer films were differentiated. The rather large degree of variability existing in grocery bags, even though they are mass produced, was shown, confirming that these items can be useful in tracing the source of illicit drug doses.     

心肌梗死的红外光谱检测

目的建立鉴定心肌梗死的红外光谱法,探讨傅里叶红外光谱面扫描技术鉴别早期心肌缺血和陈旧性心肌梗死的可行性。方法利用傅里叶变换显微红外光谱面扫描成像技术对1例心肌梗死组织样品进行逐点扫描,观测细胞酰胺A带、CH3反对称伸缩、胶原蛋白三螺旋结构及核酸和磷酸脂质PO2反收缩振动频率的光谱分布情况,绘制梗死组织的红外光谱病理图像。结果酰胺A带及胶原蛋白三螺旋结构的高吸收区、CH3反对称伸缩及核酸和磷酸脂质PO2反收缩振动的低吸收区与梗死区符合。结论傅里叶红外光谱及面扫描技术可鉴定心肌梗死病理改变,酰胺A带和胶原蛋白三螺旋结构的红外光谱图改变可特征性的判别早期心肌缺血和陈旧性心肌梗死。     

The evidential value of cosmetic foundation smears in forensic casework

Cosmetic foundation products are easily transferred to clothing and other surfaces as a result of contact with such objects. Examination of past cases involving cosmetics in New Zealand has shown cosmetic foundation to be one of the more common cosmetic products encountered. The aim of this research was to determine the most discriminating method for the comparison of transferred foundation with samples obtained from a known source in forensic casework. Fifty-three foundation samples were analyzed by Fourier transform infrared spectroscopy (FTIR), gas chromatography with a flame ionization detector (GC-FID) and scanning electron microscopy-energy dispersive X-Ray analysis (SEM-EDX). It was found that a 5 mm2 section of a light smearing was enough to provide detectable results. The discriminating powers for FTIR, SEM-EDX and GC-FID were 98.3, 93.8, and 82.0% respectively. A combination of all three techniques provided a discriminating power of 99.7%, meaning that almost complete discrimination was achieved between the foundation samples.     

Visualization of Fingermarks Deposits on Untreated Thermal Paper Exploiting the Near Infrared Luminescence

Thermal paper is widely used as a print medium for different applications but it constitutes a tricky substrate for fingermark visualization. An earlier work (J Forensic Sci 2015; 60 :1034) reported how to visualize fingermarks on untreated thermal paper by illuminating the item with a UV-A light source. In the present paper, the potential of the near infrared (NIR) luminescence has been tested on thermal paper compared to the mentioned method. A controlled study was carried out utilizing eccrine enriched fingermarks. The promising outcomes obtained were further confirmed by performing a pseudo-operational trial. Data clearly showed that the use of the NIR filter gave better results. Finally, preliminary tests suggested a different mechanism of reaction induced by fingermarks with respect to the one behind the thermal printing. Thus, NIR luminescence represents a refinement to the suite of optical examination processes, including the potential to increase the number of marks recovered in a noncontact, nondestructive way.     

Comparison of near infrared light photography and middle infrared light photography for deciphering obliterated writings

There are obliterated writings that are undecipherable by conventional visible and near infrared monochromatic light photography. Some of them could be deciphered undestructively by middle infrared light photography. Characters were written on paper with 101 kinds of pens. Middle infrared light photographs and near infrared light photographs of them were taken and compared to recognize what kinds of inks is transparent at examined wavelength regions. Based on the results obtained, the combination of ink for drawing and obliterating (which is not deciphered by visible and near infrared light photography, but expected to be deciphered with middle infrared light photography) is selected. From the examined photographs, it is demonstrated that there exist obliterated writings which are undecipherable by conventional near infrared light photography, but decipherable by middle infrared light photography.     

Forensic analysis of bicomponent fibers using infrared chemical imaging

The application of infrared chemical imaging to the analysis of bicomponent fibers was evaluated. Eleven nominally bicomponent fibers were examined either side-on or in cross-section. In six of the 11 samples, infrared chemical imaging was able to spatially resolve two spectroscopically distinct regions when the fibers were examined side-on. As well as yielding characteristic infrared spectra of each component, the technique also provided images that clearly illustrated the side-by-side configuration of these components in the fiber. In one case it was possible to prepare and image a cross-section of the fiber, but in general the preparation of fiber cross-sections proved very difficult. In five of the 11 samples, the infrared spectra could be used to identify the overall chemical composition of the fibers, according to a published classification scheme, but the fiber components could not be spatially resolved. Difficulties that are inherent to conventional "single-point" infrared spectroscopy, such as interference fringing and sloping baselines, particularly when analyzing acrylic type fibers, were also encountered in the infrared chemical image analysis of bicomponent fibers. A number of infrared sampling techniques were investigated to overcome these problems, and recommendations for the best sampling technique are given. Chemical imaging results were compared with those obtained using conventional fiber microscopy techniques.     

Structural determination of the principal byproduct of the lithium-ammonia reduction method of methamphetamine manufacture

One common method of illicit methamphetamine manufacture utilizes an alkali metal, typically lithium, and liquid ammonia to chemically reduce ephedrine or pseudoephedrine to form methamphetamine. This method is often referred to as the lithium-ammonia reduction method or the Birch reduction method. While the hydroxyl group of ephedrine is more reactive than the aromatic ring, excess alkali metal and the presence of a proton source allow the formation of a cyclohexadiene byproduct not found in samples of methamphetamine produced from other manufacturing methods. A sample enriched in this byproduct was generated and characterized using nuclear magnetic resonance (NMR) spectroscopy, gas chromatography-mass spectrometry (GC-MS), infrared (IR) spectrophotometry, and ultraviolet (UV) spectrophotometry. The chemical structure of this byproduct was determined to be 1-(1',4'-cyclohexadienyl)-2-methylaminopropane (CMP).     

Forensic applications of infrared chemical imaging: multi-layered paint chips

This paper examines the potential of infrared chemical (hyperspectral) imaging as a technique for the forensic analysis of automotive paint chips in particular, and multicomponent (e.g., layered) samples in general. Improved sample preparation procedures for the infrared analysis of paint chips are detailed, with the recommendation that where mounting resins are chemically incompatible with the sample, it is better to mount and section the sample in a soft wax from which the sections can be removed and pressed into a KBr disk for transmission analysis. Infrared chemical images of multilayered paint chips have been successfully obtained, with the chief advantage over conventional infrared analysis being that thousands of infrared spectra are collected in a few minutes across the whole sample, at a spatial resolution of around 5 microm. As with conventional infrared spectroscopy, chemical species can be identified from their spectra, but the wealth of information available can be also extracted in a number of different ways that make multicomponent spectral (and hence chemical) comparisons between two samples easy to visualize and understand. In one approach, the infrared chemical images of two paint chips being compared side-by-side can be viewed as a "movie," in which each frame is an intensity map of the two samples at a given wavenumber (frequency) value. In another approach, the spectra (pixels) in the image files are classified into chemically similar groups, resulting in a "cluster" image that makes it possible to simultaneously compare all of the layers in two paint chips. These methods are applicable to other multicomponent samples, and also to other chemical imaging techniques.     

傅里叶红外图像无损检验添改数字的研究

目的建立利用傅里叶红外图像系统无损检验添改数字的检验方法。方法采集同种同品牌、同种不同品牌及不同种书写材料书写的数字1改为4和3添加为8两类样本的红外图像，根据红外吸收的光谱信息对其添改进行检验。结果同种不同品牌及不同种书写材料对红外吸收强弱不同，形成的红外图像有差别；同种同品牌书写材料对红外吸收强弱没有明显差别。结论该检验方法不损坏检材，重现性好，并且纸张成分对其分析结果基本上无干扰。     

Evaluation of the Dr?ger Alcotest model 7110 infrared breath alcohol analysing instrument

Until 1986, commercially-available infrared breath alcohol analysing instruments employed wavelengths in the region of 3.4 mu. The move to the 9.5 mu region in the Dr?ger Alcotest 7110 promised greater discrimination against endogenous compounds such as acetone. The present study confirmed that acetone interference is insignificant and that in terms of in vitro accuracy and precision, the ten 7110 units tested were superior to the Breathalyzer 900, the instruments they will replace for evidential testing in South Australia. The new unit meets the South Australian Police demand for portability and its shielding prevents interference fron any of the common radio frequency transmissions in Adelaide when operating as near to the source as possible. Comparisons of breath results (monthly averages) and their corresponding blood results accumulated during the first few months of operation showed no bias between the two techniques.     

Lower limits of detection of synchrotron radiation high-energy X-ray fluorescence spectrometry and its possibility for the forensic application for discrimination of glass fragments

Synchrotron radiation high-energy X-ray fluorescence (SR-XRF) analysis utilizing 75.5keV X-ray radiation from beam-line BL37XU at Super Photon Ring 8GeV (SPring-8), a third-generation synchrotron facility, was found to have advantages for forensic discrimination of glass samples. The lower limits of detection (LLD) for calibration curves were at the picogram level for Ba, Ce, and Sm and at the 10pg level for Sr, Zr, Sn, and Hf. The spectrum of NIST SRM 612 glass reference material demonstrated K-line peaks of 31 elements including rare-earth elements, and the relative standard deviations (R.S.D.) of all the measured elements except Ca were less than 9.7%. Fragments of collected sheet glass were used as samples for investigating the application of this technique to forensic analysis. Several trace elements such as Pb, Rb, Sr, Zr, La, Ce, and Hf were detected in the spectra of the samples, and these elements could be used as indexes to characterize the glass samples. But the "lower limits of detection (LLD)" of each element were not examined enough. In this report, these limits by synchrotron radiation X-ray spectrometry were clarified. By these results, this technique should provide an effective approach to the nondestructive discrimination of small glass fragments in the field of forensic science.     

Analysis of hydrogen cyanide in air in a case of attempted cyanide poisoning

A 32-year-old man attempted to poison his ex-girlfriend with hydrogen cyanide by hiding the pesticide Uragan D2 in her car. During the police investigation, chemical analysis of the air inside the car was performed. Hydrogen cyanide was detected through on-site air analysis using a portable Fourier transform infrared (FTIR) spectroscopy gas analyzer and colorimetric gas detection tubes. Furthermore, impinger air-sampling was performed for off-site sample preparation and analysis by gas chromatography-mass spectrometry (GC-MS). All three independent techniques demonstrated the presence of hydrogen cyanide, at concentrations of 14-20ppm. Owing to the high volatility of hydrogen cyanide, the temperature and the time since exposure have a substantial effect on the likelihood of detecting hydrogen cyanide at a crime scene. The prevailing conditions (closed space, low temperature) must have supported the preservation of HCN in the car thus enabling the identification even though the analysis was performed several days after the hydrogen cyanide source was removed. This paper demonstrates the applicability of combining on-site FTIR measurements and off-site GC-MS analysis of a crime scene in order to ensure fast detection as well as unambiguous identification for forensic purposes of hydrogen cyanide in air.     

Development of heavy mineral and heavy element database of soil sediments in Japan using synchrotron radiation X-ray powder diffraction and high-energy (116 keV) X-ray fluorescence analysis: 1. Case study of Kofu and Chiba region

We have started the construction of a nationwide forensic soil sediment database for Japan based on the heavy mineral and trace heavy element compositions of stream sediments collected at 3024 points all over Japan obtained by high-resolution synchrotron X-ray powder diffraction (SR-XRD) and high-energy synchrotron X-ray fluorescence analysis (HE-SR-XRF). In this study, the performance of both techniques was demonstrated by analyzing soil sediments from two different geological regions, the Kofu and Chiba regions in Kanto province, to construct database that can be applied in the future to provenance analysis of soil evidence from a crime scene. The sediments from the quaternary volcanic lithology of the Chiba region were found to be dominated by heavy minerals of volcanic origin - orthopyroxene, clinopyroxene, and amphibole, and the REEs (rare earth elements) within the region showed similar geochemical behavior. On the other hand, four distinct heavy mineral groups were identified in the sediments of the Kofu region, where there is a great variety of underlying bedrock, and the geochemical behavior of the REEs in the sediments also varied accordingly to their geological origins. As such, our study shows that high-resolution SR-XRD data can provide information on the spatial distribution patterns of heavy minerals in stream sediments, playing an important role in determining their likely geographical origin. Meanwhile, the highly sensitive HE-SR-XRF data allow us to study the geochemical behavior of trace heavy elements, especially the REEs in the sediments, providing additional support to further constrain the likely geographical origin of the sediments determined by heavy minerals.     

Source Determination of Red Gel Pen Inks using Raman Spectroscopy and Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy combined with Pearson's Product Moment Correlation Coefficients and Principal Component Analysis

The potential combination of two nondestructive techniques, that is, Raman spectroscopy (RS) and attenuated total reflectance–fourier transform infrared (ATR‐FTIR) spectroscopy with Pearson's product moment correlation (PPMC) coefficient (r) and principal component analysis (PCA) to determine the actual source of red gel pen ink used to write a simulated threatening note, was examined. Eighteen (18) red gel pens purchased from Japan and Malaysia from November to December 2014 where one of the pens was used to write a simulated threatening note were analyzed using RS and ATR‐FTIR spectroscopy, respectively. The spectra of all the red gel pen inks including the ink deposited on the simulated threatening note gathered from the RS and ATR‐FTIR analyses were subjected to PPMC coefficient (r) calculation and principal component analysis (PCA). The coefficients r = 0.9985 and r = 0.9912 for pairwise combination of RS and ATR‐FTIR spectra respectively and similarities in terms of PC1 and PC2 scores of one of the inks to the ink deposited on the simulated threatening note substantiated the feasibility of combining RS and ATR‐FTIR spectroscopy with PPMC coefficient (r) and PCA for successful source determination of red gel pen inks. The development of pigment spectral library had allowed the ink deposited on the threatening note to be identified as XSL Poppy Red (CI Pigment Red 112).     

The detection and enhancement of latent fingermarks using infrared chemical imaging

The use of a new technique, Fourier transform infrared (FTIR) chemical imaging, has been demonstrated for the enhancement of latent fingermarks on a number of surfaces. Images of untreated fingermarks on glass backgrounds with excellent ridge detail were acquired using infrared chemical imaging. High quality fingermarks on glass backgrounds were also developed using ethyl cyanoacrylate (super glue) fuming and subsequent infrared chemical imaging. This new method allows the collection of images from backgrounds that traditionally pose problems for current fingermark detection methods. The background may, for example, be highly colored, have a complex pattern, or possess other pattern or image characteristics that make it difficult to separate fingermark ridges using traditional optical or luminescent visualization. One background that has proven to be a challenging surface for the development of latent fingermarks is the Australian polymer banknote. To demonstrate the power and applicability of infrared chemical imaging, fingermarks fumed with ethyl cyanoacrylate were successfully imaged from Australian polymer banknotes.     

A Novel Approach to the Examination of Soil Evidence: Mineral Identification Using Infrared Microprobe Analysis*

Abstract: Identification of minerals using the infrared microprobe with a diamond internal reflection objective is a rapid and reliable method for forensic soil examinations. Ninety‐six mineral varieties were analyzed, and 77 were differentiated by their attenuated total reflection (ATR) spectra. Mineral grains may be mounted in oil for conventional polarized light microscope characterization and their ATR spectrum obtained with little or no interference by the liquid. This infrared microprobe method can be used to identify silicates, phosphates, nitrates, carbonates, and other covalent minerals; however, ionic minerals, metal oxide and sulfide minerals, and minerals with refractive indexes greater than diamond do not produce identifiable spectra, but the lack of a spectrum or one with high absorbance values does provide useful information. This research demonstrates the overall utility that infrared microprobe analysis brings mineral identification in soil evidence.