Gasoline has high inflammability and combustibility. Therefore, when gasoline is spilled on a floor, it may form a great flame and cause a big fire. In this case, it is thought that the spill area influences the flame height.
  In this study, the authors carried out combustion tests of gasoline and kerosene spilt on a wooden floor coated with a galvanized iron sheet. Liquid fuel was spilled in a circle surrounded by a clay fence. The spill area was determined by changing the radius of the fence. We placed heat flux meters in and around the flame and measured heat flux and radiation heat from the flame. We measured the temperature of the flame by using K-type thermocouples. The flame behavior was recorded on video and mean flame height was measured. Furthermore, we measured the weight loss rate of gasoline and obtained the heat release rate.
Conclusions are as follows:
(1) When the radius of the spill area was 0.8 m, the mean flame tip height reached 4.7 m. The flame height was higher as the spill area increased in size, but the quantity of the gasoline spill was not a factor.
(2) The mean flame tip height was calculated using the heat release rate measured in the combustion tests. The calculated value agreed approximately with the experimental value.
(3) When the radius of the spill area was 0.8 m, a high temperature region more than 400°C spread to a 3 m height from the floor and the average heat flux at 3.5 m height had the highest value of 74.7 kW/m².
(4) The radiant heat at a distance of 50 cm from the apparent flame surface was so high, 20-30 kW/m², it was found that there was ignitability to combustibles within this distance.

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  High-performance liquid chromatography/mass spectrometry (LC/MS) was applied to the forensic discrimination of dishwashing detergents. Each dishwashing detergent, commercialy available in Japan, consists of anionic, nonionic, amphoteric surfactants or a combination of these surfactants. These surfactants were separated on a reversed-phase C₁₈ column with methanol/10 mM ammonium acetate gradient mobile phase and were identified according to their molecular-related ions and retention times. Sixty-three commercial products were analyzed and 1,928 of all possible 1,953 pairs (ca. 99%) were distinguished without using other analytical methods. All of the indistinguishable products (25 pairs) were variation of products from a same manufacture with different fragrance, and/or concentration, and a product of original equipment manufacturer (OEM). These results indicate that LC/MS is a reliable tool for the forensic discrimination of surfactants in dishwashing detergents.

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  A genotype of JC virus (JCV) DNA extracted from human urine can serve not only as a means of elucidating human migration patterns, but also of tracing the origin of unidentified cadavers. If a JCV genotype is determined using a small amount of urine or urine stain from a given person, it may be useful in identifying the geographic area in which that person was born. In the present study, we amplified a 610-bp intergenic region (IG region) of JCV DNA extracted from 200 μl of each of 82 urine samples collected in Japan. JCV DNA was detected in 45 of 82 urine samples (54.9%) and genotypes were also determined by restriction fragment length polymorphism analysis (MY genotype: 13; X (CY) genotype: 25; unclear: 7). Additionally, 16 urine stains which had been prepared 3 months earlier using 100 μl of JCV-positive urine were examined. JCV DNA was detected in 11 of 16 urine stains (68.8%), and in this case also, it was possible to determine the genotype by the phylogenetic analysis after DNA sequencing.
  The present study indicates that JCV genotyping can be successfully conducted using only 100 μl urine stain and even 3 months after the urine stain was made. Thus, JCV genotyping shows promise as a new analytical method for narrowing down the native place of unidentified persons or cadavers from urine stains left at the scene.

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  Elemental analysis of solid blue paint chips for a truck was carried out by scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX).
  We could detect 6 elements (Cl, Ti, Fe, Cu, Br and Ba) used for color pigments such as phthalocyanine blue (chlorinated copper phthalocyanine) and phthalocyanine green (brominated copper phthalocyanine) from the paint chips collected.
  It was found that the characteristic patterns, elements and the X-ray intensity ratios of these elements could be useful to discriminate solid blue paints.
  Elemental analysis by SEM/EDX allowed us to discriminate solid blue paints for a truck, even if the sample was a very tiny smeared one.

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  The effects of the various preparation procedures of the Dragendorff reagent on sensitivity for thin layer chromatography (TLC) were examined. The sensitivity to various compounds was different depending on the preparation procedures of the Dragendorff reagent.
  The reagent with the highest sensitivity to most of the compounds tested was the one prepared with bismuth subnitrate and concentrated hydrochloric acid. However, color spots were disappeared relatively in a short time after the reagent was sprayed on the compounds. The reagent with the second highest sensitivity was the one prepared with precipitation of Bi(OH)₃ from bismuth subnitrate, although the procedure was complicated and time-consuming.
  Consequently, to simplify the preparation procedure of the reagent, we modified it to the procedure without precipitation of Bi(OH)₃ from bismuth subnitrate. The reagent was also prepared from commercially-manufactured Bi(OH)₃ or BiI₃. The modified Dragendorff reagents showed almost the same sensitivity to most of the compounds tested as the one prepared with precipitation of Bi(OH)₃ from bismuth subnitrate, and would be useful for practical TLC analysis.

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  Low concentration of volatile organic components (VOC) usually need to be condensed before analyzing them by using gas chromatography (GC). NeedlEx^TM is a recently developed needle for adsorbing VOC. Gas components are easily adsorbed and condensed while passing through the adsorbents in the needle.
  This paper describes the successful results of trying to adsorb and analyze light mineral oils by the use of NeedlEx^TM. They are often used for arson cases. The gas phase of soil containing gasoline, kerosene or gas oil was adsorbed using NeedlEx^TM, and was analyzed by GC. Through easy procedures, the VOC of their oils were efficiently condensed. Furthermore, NeedlEx^TM was successfully applied to adsorb and analyze kerosene contained in the clothes of a fire victim by using GC. NeedlEx^TM was found to be a useful device for the adsorption and analysis of light mineral oils.

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  In a poisonous crime case, clarifying identity of the poisonous materials between actually used in the crime scene and the confiscated from the suspect's neighborhood is required.
  In this report, the examination of the discriminating capability of these compounds was conducted, using 13 As₂O₃ samples of known origins and manufacturing methods.
  By the observation using the scanning electron microscope, three morphological differences were recognized. The first one exhibited an euhedral crystal with octahedral shape, the second one had spherical shape and the third one was crystal showing significant cleavages. Furthermore, by energy-disperse X-ray analysis disclosed, only L_α,β and weak K_α,β peaks of arsenic in all samples, and the discrimination was impossible. Because of this reason, inductively coupled plasma-atomic emission spectrometry (ICP-AES) was adopted for the discrimination of the As₂O₃ samples by trace impurities. The compared heavy elements were barium (Ba), lead (Pb), antimony (Sb), selenium (Se) and tin (Sn) which were selected by a pre-qualified analysis of arsenous samples.
  As a result, significant difference was observed among these samples by comparison of the 5 elements, and their patterns were classified into three categories.
  It was considered that estimation of the origins and manufactured methods were possible from the morphological observation by scanning electron microscope and the comparison at trace impurities by ICP-AES.

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  Molten marks on electric plugs or wall sockets found in fire sites often are great help, when we investigate the cause of the fires. It is known that the distance between each second arm of crystals called DAS (Dendrite Arm Spacing), that we see on the cross section of those molten marks, change depending on the atmospheric temperature at the time of a short circuit. Also it is already known that DAS between primary and secondary marks are clearly different. We created reference data to make use of DAS for practical investigation. In this study, we showed the relation between atmospheric temperature and DAS by making samples of molten marks at various temperatures. And we examined if this method was able to help assume the surrounding temperature at the time when the molten mark was produced. As a result, we found that the method has some possibility.
  We developed a new method for assuming the atmospheric temperature at the time of the short circuit using the reference data.

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  Y chromosome-specific short tandem repeat (Y-STR) analysis has become a widely accepted tool for forensic DNA analysis. The PowerPlex Y System is a fluorescent multiplex PCR kit that enables simultaneous amplification of 12 Y-STR loci (DYS19, DYS385a/b, DYS389I/II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438 and DYS439). In this study, we evaluated the application of this kit to forensic evidential samples.
  The complete profiles were successfully determined using the recommended condition of 30 PCR cycles in the modified 12.5 μL reaction volumes. Using this protocol, it was possible to type all Y-STR loci from 62.5 pg of male DNA. The male/male DNA mixtures produced full profiles from the minor component up to the 1: 2.5 ratio, which contained 0.2 ng of minor male DNA and 0.5 ng of major male DNA. The minor male component in a male/female DNA mixture was detected in all loci up to the 1:3200 ratio, which contained 125 pg of male DNA and 400 ng of female DNA. Experimentally decomposed DNA samples produced full Y-STR profiles using 10 ng or 2 ng template DNA and 32 cycles of PCR amplification.
  The 12 Y-STR systems were investigated in 92 unrelated Japanese males (Hiroshima Prefecture). Gene diversity and haplotype diversity values were calculated from the allelic frequency for each locus. The DYS385 locus was proved to be highly polymorphic (0.9451), and the other loci showed gene diversity values ranging from 0.1229 to 0.7863. A total of 88 haplotypes was observed and the haplotype diversity was calculated to be 0.9990.
  These results suggested that the PowerPlex Y System was possible to discriminate most of the male individuals in the Japanese population and can be used in forensic investigation, such as analysis of male/male or male/female DNA mixture and decomposed DNA samples.

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  A rapid and simple method for the determination of the harbicides paraquat (PQ) and diquat (DQ) in whole blood by capillary electrophoresis (CE) has been developed. The separation of PQ and DQ was performed using citrate buffer (pH 5.0) and poly ethylene glycol coated fused silica capillary (CEP). Whole blood samples were injected into the CE after pretreatment of dilution and ultra-filtration. Linearity of quantification was obtained in the concentration range of 1-100 μg/ml for PQ and DQ in whole blood with the correlation coefficients of more than 0.999. The detection limits of PQ and DQ in whole blood were 0.5 μg/ml(s/n=3). The within-day precisions of peak areas for PQ and DQ in whole blood were 2%, and the between-day precisions were 3%, 6%, respectively.

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