Yoshiteru Marumo

Screening of soil evidence by a combination of simple techniques: validity of particle size distribution

The validity of the determination of particle size distribution for forensic soil identification was studied using 73 soil samples collected from a 20 km x 15 km area. Soil particles were first divided into two fractions by wet sieving with a sieve with a 0.05 mm aperture size. Dry sieving was used to analyze the coarse particle fraction and a particle size analyzer was used for the fine particle fraction. The number of particle size classes measured by sieving could be reduced to three, <0.05, 0.05-0.2, and 0.2-2 mm, which enabled 87.9% of the soil samples to be discriminated. Measurements made with the particle size analyzer on the fine particle fraction increased the discriminating power to 95.9%. The use of particle size analysis by sieving in combination with color examination allowed us to discriminate 99.5% of the soil samples, even when particle size analysis of the fine particle fraction was not carried out.

Analysis of inorganic impurities in seized methamphetamine samples

Abstract Classification of seized methamphetamine by impurity profiling can provide very useful information on drug intelligence. In this report, the validity of inorganic impurity analysis in discriminating seized methamphetamine samples in Japan was investigated using inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS). Triplicate sampling was carried out on 17 methamphetamine samples seized in Japan. About 20 mg of methamphetamine was taken, and was dissolved in 20 ml of water. After the qualitative analysis, Ba, Sb, Pd, Sr, Br, Zn and Cu were determined by ICP-MS, and Na was determined by AAS. Among eight elements determined in this study, most cations showed large heterogeneity in their content. On the other hand, the contents of Na which is abundant in methamphetamine samples, showed relatively small intra-sample variation, and that of Br also showed good homogeneity. On the basis of the concentration of Br and Na, 17 seized methamphetamine samples were classified into five groups. Trace elements such as Tl, Hg, Au or Cs were qualitatively detected by ICP-MS. These elements can provide useful information to impurity profiling of seized methamphetamine, because these elements are characteristically present in each sample. Application of ICP-MS and AAS to the analysis of inorganic impurities can be helpful in giving additional information to the impurity profiling of seized methamphetamine by organic impurity analysis.

Identification of lipstick smears by fluorescence observation and purge-and-trap gas chromatography

Abstract Nondestructive methods of forensic identification were tested on 174 samples of lipsticks from 11 Japanese cosmetics manufacturers. Sample color was observed under white light and fluorescence was observed using light at wavelengths of 350, 445 and 515 nm. Purge-and-trap gas chromatography was used as a direct analytical technique for lipstick smears without any pretreatment. No interference was observed in chromatographic patterns when substrates such as wool, cigarette tips or filter paper were analyzed together with lipstick. Combining all of the techniques studied allowed us to discriminate between 15,038 pairs of samples out of 15,051. We conclude that this method is suitable for identification of trace amounts of lipsticks for forensic science investigation.

Microspectrophotometric discrimination of single fibres dyed by indigo and its derivatives using ultraviolet-visible transmittance spectra

Single fibres dyed by indigo and its seven derivatives were measured by microspectrophotometric examination of transmittance spectra in the ultraviolet-visible region (240-760 nm). Glycerin was the most suitable embedding reagent for this measurement. Small intra-sample variation of the transmittance intensity in single woollen fibres was observed, but relatively large inter-sample variation was observed among the fibres obtained from different areas in the same textile. There were no differences in the hmax, hmin and the position of shoulders observed in their spectra. This method was applied to the discrimination of single cotton fibres dyed by vat dyes, such as indigo and seven indigo derivatives which had similar structures. On the basis of the ultraviolet-visible transmittance spectra, these sample fibres could be distinguished from one another. It is a non-destructive method compared with chromatographic dyestuff extraction methods; furthermore, utilization of the ultraviolet region gave spectra providing useful information for evaluating fibre evidence.

Morphological Analysis of Opal Phytoliths for Soil Discrimination in Forensic Science Investigation

A morphological analysis of opal phytoliths in soils was applied to forensic science soil discrimination. To examine a variation of opal phytolith composition with a difference of land use or topography, a region was chosen in a range of 5 km covering from diluvial plateau to alluvial plain. Opal phytolith compositions in soil samples collected from the same site were similar. On the other hand, there were obvious differences in the compositions between soils from different sites. In the region examined, contents of Chloridoid, Bambusoid, Fan-shape, and Elongate classes varied with sampling sites allowing us to discriminate the samples from different sites. Festucoid and Point-shape class were small in the amounts to be compared for the soil discrimination. Morphological analysis of opal phytoliths was effective to discriminate soil samples that came from different land use, even though they were indistinguishable by their mineralogical characteristics. About 2 mg of opal phytolith fraction, 10 to 200 µm in diameter, less than 2.3 in specific gravity, was a sufficient amount for the morphological analysis.

Clay Mineralogical Analysis Using the <0.05-mm Fraction for Forensic Science Investigation—Its Application to Volcanic Ash Soils and Yellow-Brown Forest Soils

Clay mineralogical analysis is conducted with a fraction size of less than 0.05 mm in diameter (

Rapid Clay Mineralogical Analysis for Forensic Science Investigation—Clay Mineralogy Over the Short Distances

Rapid clay mineralogical analysis using a particle size fraction less than 0.05 mm without extraction of a clay fraction (

A method for forensic identification of vegetable oil stains--rapid analysis of carboxylic acids with methyl esterification using purge-and-trap gas chromatography/mass spectrometry.

A simple method using purge-and-trap gas chromatography/mass spectrometry (P&T-GC/MS) for forensic examination of oil stains was studied. Carboxylic acids, chosen as target components for discrimination of oil samples, were extracted from stains with ether, methyl esterified by tetramethylammonium hydroxide, and analyzed by P&T-GC/MS. Vegetable oils were discriminated according to their carboxylic acid compositions. Carboxylic acid composition was independent of the substrate material of the stain. Although the carboxylic acid composition of the oil changed on exposure to sunlight, identification of oil was possible for oil stains that had been in the shade, if analysis was made within 20 days.