Japanese Journal of Forensic Science and Technology
Online ISSN : 1881-4689
Print ISSN : 1880-1323
ISSN-L : 1880-1323
Volume 25, Issue 2
Displaying 1-10 of 10 articles from this issue
Original Article
  • Hidenao Kakehashi, Noriaki Shima, Hiroe Kamata, Hiroshi Nishioka, Akar ...
    2020 Volume 25 Issue 2 Pages 141-150
    Published: 2020
    Released on J-STAGE: July 31, 2020
    Advance online publication: January 11, 2020
    JOURNAL FREE ACCESS

     A new and simple analytical method for the detection of cyanide has been developed using a dimethoxytiazinyl (DMT) derivatization technique. The DMT derivatives of cyanide (DMT-CN) produced in the reactions of cyanide with 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium (DMT-MM) known as a harmless condensing reagent were detected by gas chromatography-mass spectrometry with a slightly-polar capillary column, and were identified using an authentic DMT-CN standard synthesized in our laboratory. The conditions affecting the derivatization reaction were optimized (pH 9; temperature, 25 ℃; reaction time, 20 min) by investigating the yield of the DMT-CN. The optimized method exhibited a high degree of linearity (r2=0.9980-0.9999) for cyanide in distilled water and three beverages (tea, coffee and milk) without major interference of matrix compounds, over the concentration range from 6.0 to 600 μg/mL. The limits of detection were estimated to be 0.2 μg/mL for distilled water and 0.3 μg/mL for the beverages. The obtained values for accuracy and precision were less than 10% for two concentration levels (30 and 300 μg/mL) in the beverages. These results guarantee the satisfactory sensitivity, reproducibility and reliability of the present method. The method could be also applicable for the detections of cyanide, azide and sulfide in blood samples. This report demonstrates high-throughput, high-sensitive, applicable, cheap and safe properties of the DMT-derivative method for cyanide determination.

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  • Yoshiaki Iwamuro, Takaya Murakami, Reiko Ishimaru, Yuki Sakamoto, Sato ...
    2020 Volume 25 Issue 2 Pages 151-158
    Published: 2020
    Released on J-STAGE: July 31, 2020
    Advance online publication: February 21, 2020
    JOURNAL FREE ACCESS

     We have developed an analytical method for the determination of hydrogen sulfide in whole blood by headspace-gas chromatography/mass spectrometry (HS-GC/MS) using an Rt-Q-BOND column (a nonpolar porous layer open tubular column incorporating 100% divinylbenzene). This system allows the baseline-separation of hydrogen sulfide, hydrogen cyanide, hydrogen arsenide, and hydrogen azide, as well as alcohols and organic solvents of forensic interest. The sample preparation procedure, which only involves mixing of the blood specimen with acetone and phosphoric acid, is simple and convenient. The addition of acetone to the blood specimen significantly improved the analytical sensitivity of this system for hydrogen sulfide. The lower limit of detection and limit of quantification of hydrogen sulfide in blood were 0.05 μg/mL and 0.1 μg/mL, respectively. A calibration curve was obtained in the range of 0.1-10 μg/mL. Satisfactory intraday and interday reproducibilities were demonstrated for the present method through relative standard deviations, which were lower than 10%. Thus, this method was found to be suitable for the determination of hydrogen sulfide in forensic blood specimens.

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  • Keiko Sasaki, Akari Ishikawa, Noriaki Shima, Hiroe Kamata, Atsushi Nit ...
    2020 Volume 25 Issue 2 Pages 159-170
    Published: 2020
    Released on J-STAGE: July 31, 2020
    Advance online publication: February 18, 2020
    JOURNAL FREE ACCESS
    Supplementary material

     In order to establish the method for discriminating between oral ingestion (internal use) and dermal absorption (external use) of diphenhydramine (DPH) using biological fluids, the excretion profiles of unchanged DPH and its metabolites in urine as well as time-course changes in blood concentration of DPH have been investigated. Urine and blood specimens were obtained from volunteer users of either the sleep-inducing drug Drewell tablet or the antipruritic drug New Restamin Kowa ointment. Unchanged DPH and its metabolites were identified and quantified using liquid chromatography-tandem mass spectrometry with a C18 semi-micro column. DPH and its three metabolites, diphenhydramine N-oxide, N-desmethyl diphenhydramine and diphenhydramine N-glucuronide, have been detected, for the first time, in urine after dermal absorption, and the urinary excretion profiles of DPH and the metabolites were observed along with those after oral ingestion. Maximum concentration times of DPH and its metabolites in urine were between 21 and 73 hours in dermal absorption, and between 4 and 21 hours in oral ingestion. Maximum concentration times of DPH in blood for dermal absorption were also larger than those for oral ingestion. These results suggested that absorption of DPH through the skin occurs more slowly and continuously compared with oral ingestion. In addition, the maximum concentrations of DPH and its metabolites in urine after oral ingestion were ten to hundred times higher than those after dermal absorption, which suggests that the urinary concentration of DPH and its metabolites could be applicable as the indexes which allow to discriminate between internal and external uses. The findings obtained in this study will be indispensable as the fundamental information for discussing intake situations of DPH in the forensic fields.

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  • Shota Inokuchi, Natsuko Mizuno, Kazumasa Sekiguchi
    2020 Volume 25 Issue 2 Pages 171-183
    Published: 2020
    Released on J-STAGE: July 31, 2020
    Advance online publication: February 18, 2020
    JOURNAL FREE ACCESS

     New features for forensic STR typing have become available on 3500 Series Data Collection Software version 4 (DC v4). To investigate impacts of the new features on the interpretation of electropherograms is important to maintain and improve the objectivity and reliability of forensic STR typing. In this study, we assessed and investigated fundamental performance, signal optimization, and pull-up reduction with enabling and disabling the new data optimization features. In fundamental performance verification, although the data generated with the run module-dependent signal optimization showed a tendency to decrease the peak height slightly, all the data set generated from a different combination of enabled and disabled features tested in this study were comparable. In electropherograms generated with the run module-dependent signal optimization, some artifact peaks were observed at lower molecular weight region from the presumed parent allele peaks in the same dye-channel. The number of pull-up peak observations in electropherograms generated with the pull-up reduction feature was decreased compared to when the feature was disabled. However, distributions of distances of a pull-up peak from the corresponding parent peak and morphologies of pull-up peaks were different between the dataset obtained from the pull-up reduction feature enabled and that obtained from the feature disabled in certain pull-up patterns. Therefore, forensic biologists must be aware of those differences when interpreting electropherograms. We conclude that it is useful to use DC v4 with the run module-dependent signal optimization feature disabled and the pull-up reduction feature to obtain electropherograms with less artifact peaks.

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  • Akari Ishikawa, Tooru Kamata, Atsushi Nitta, Ryutaro Asai, Misato Wada ...
    2020 Volume 25 Issue 2 Pages 185-191
    Published: 2020
    Released on J-STAGE: July 31, 2020
    Advance online publication: June 10, 2020
    JOURNAL FREE ACCESS

     In the analysis of ephedrine (EP) by gas chromatography/mass spectrometry (GC/MS), methcathinone (MC), a narcotic, has been detected as its artifact, and we investigated the formation mechanism of MC from EP. The effective analytical procedure which allows us to prevent its formation has been also examined. The injection temperature of the GC instrument was varied with different extraction solvents from aqueous EP solution, and the amount of MC as the artifact was measured.

     As a result, the formation of MC from EP is attributed to 1) oxidation of EP by the oxidative impurities in the extracting solvent, and 2) oxidation of EP in the extremely high temperature of the GC injection appeared larger. Furthermore, as the procedure for preventing the formation of MC from EP, the injection method and derivatization of OH group of EP were also investigated.

     In the extraction of EP, it was found that the use of high grade of extracting solvents such as ethyl acetate for synthesis grade, which contain the extremely low concentration of impurities that include dissolved oxygen and peroxide that cause oxidation of EP, is significantly effective for preventing the formation of MC from EP. Also, the use of split injection into GC in combination with protecting the OH group of EP by trifluoroacetyl derivatization allowed to prevent the formation of MC.

     This study indicates that when a small amount of MC was detected in the GC/MS analysis of samples which contain high concentration of EP, careful examination will be needed in consideration of the possibility of the MC formation during the analysis. It will, also, be helpful for forensic analysis of other EP analogues including norephedrine and methylephedrine.

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Technical Note
  • Hiromi Itamiya, Kento Kumisaka, Hitomi S. Kikkawa, Ritsuko Sugita
    2020 Volume 25 Issue 2 Pages 193-200
    Published: 2020
    Released on J-STAGE: July 31, 2020
    Advance online publication: April 17, 2020
    JOURNAL FREE ACCESS

     Forensic samples may include small plant fragments collected as trace evidence that are examined by microscopy and DNA analysis. These fragments are often recovered on adhesive tapes or sheets; as such, recovery must be carried out carefully so that important morphological features, including thorns or trichomes, are not destroyed. In this study, we investigated the use of organic solvents for the recovery of small plant fragments from adhesive tapes and sheets. Particularly, we examined the influence of the solvent and of the adhesive compound on the DNA analyses. Therefore, our goal was to determine an appropriate recovery method for small plant fragments that did not have a negative impact on critical forensic analyses.

     Plant samples, including seeds and leaves, were attached to adhesive sheets or tapes and recovered with solvents such as water and organic solvents. The extent of recovery and the influence of the adhesive compound and solvent on the subsequent DNA analyses were examined. After the immersion of plant samples in the solvent to detach them from the adhesive compound, DNA extraction and polymerase chain reaction (PCR) amplification were performed.

     Among our findings, we determined that plant samples on most types of adhesive sheets can be recovered with tweezers alone and are appropriate for microscopic evaluation and DNA analysis. Organic solvents were used to recover samples attached to sheets with strong adhesives. This method had no discernible impact on DNA extraction or the subsequent PCR analyses. Thus, we concluded that small plant fragments attached to adhesive sheets or tapes can be recovered for forensic examination with a variety of methods, including the use of organic solvents.

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  • Shota Inokuchi, Natsuko Mizuno, Kazumasa Sekiguchi
    2020 Volume 25 Issue 2 Pages 201-210
    Published: 2020
    Released on J-STAGE: July 31, 2020
    Advance online publication: June 10, 2020
    JOURNAL FREE ACCESS
    Supplementary material

     One of the changes in the version update to v1.6 of GeneMapper ID-X Software (GMIDX) designed for human identification data analysis is a revision of the peak height detection algorithm. Hence, the evaluation of impact to the data interpretation of STR typing by the differences of the software version is required to utilize the latest version for routine casework. In this study, concordance study for calculated peak details and quality assessment by process quality value (PQV) flags was performed by comparing data for a total of 1844 electrophoresis run data including controls and allelic ladder analyzed using GMIDX v1.4 and v1.6, respectively. For peak details, while sizing and data point of the peaks analyzed using each version were all concordant for the peaks detected in both versions, discordance was found in allele call, peak height, and peak area. For discordance of peak height and peak area, the values calculated by GMIDX v1.6 were all smaller than those by GMIDX v1.4. Some allelic dropouts which the peak was detected by one version was not detected by the other version. For the quality assessments by PQV flags, discordance was found in only SPK in Sample-Level Quality Assessments, discordance was found in BIN, PHR, LPH, AN, BD, SPK, and ACC in Marker-Level Quality Assessments. These discordances except for peak area were caused by lower peaks derived from artifact and/or noise. Further, the impact of the version difference on the calculation of the minimum thresholds was evaluated. Although slight differences in detected peak height were observed by the revision of the peak height detection algorithm, the calculated minimum thresholds resulted in the same values.

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  • Yukinobu Kutsuwada
    2020 Volume 25 Issue 2 Pages 211-222
    Published: 2020
    Released on J-STAGE: July 31, 2020
    Advance online publication: June 16, 2020
    JOURNAL FREE ACCESS
    Supplementary material

     Tri-allelic peaks are rarely detected from single-source DNA in the case of testing with commercial STR kits, while homozygous or heterozygous peaks are frequently observed at each locus. Tri-allelic patterns can possibly occur in healthy people, and the peak balance of various tri-alleles from different origins can cause some problems that discern from artifact peaks affecting the result of STR typing, or difficulties in the evaluation of kinship.

     In this study, different samples from a volunteer with D21S11 tri-alleles (alleles 26, 29, and 30) were tested using routine STR analysis methods. The peak balances of the tri-allele varied significantly between samples, therefore a type 1 tri-allelic pattern caused by somatic mutation in the early stages of differentiation was possible because the sum of the lower two peak heights was roughly equal to the highest peak height in every case. Direct sequence analysis of the individual's family members revealed that the tri-allelic pattern was not inherited from the mother, nor was it passed down to the daughter. In addition, a mutated form of one of the tri-alleles and its mutated repeat unit and numbers were identified.

     When tri-allelic peaks are suspected, it is essential to analyze not only intra-locus peak balance but also the whole electropherogram profile. This means that STR typing is necessary considering the fact that pull-up peaks or stutter peaks could resemble tri-allelic peaks.

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Note
  • Atsushi Shinohara
    2020 Volume 25 Issue 2 Pages 223-243
    Published: 2020
    Released on J-STAGE: July 31, 2020
    Advance online publication: February 21, 2020
    JOURNAL FREE ACCESS

     Appraisal related to charring of wood may be conducted for arson cases, especially fires with a small scale of burning. When wood is carbonized, a distinctive form is observed, such as the surface turning black or cracking, but no clear appraisal method has been established, and the criteria set by individual appraisers have not been established. The current situation is that appraisal is conducted based on these individual appraisal methods. However, it is expected that the presence or absence of carbonization of the wood can be objectively determined by measuring the infrared absorption spectrum of the burned wood using a Fourier transform infrared spectrophotometer. Therefore, in this study, an experimental model was constructed on the assumption of an actual arson case, a combustion experiment was performed on wood, which is widely used as a building material, and data on the obtained carbides were examined and objectively carbonized. We have devised a carbonization appraisal method. In this study, in addition to FT-IR analysis, SEM-EDX analysis and XRD analysis were also used to analyze detailed carbides. As a result, FT-IR analysis showed that objective wood can be identified for carbonization. However, when heated by a high temperature flame, the wood transitions to complete carbide, but when heated by a relatively low temperature flame as in the experimental model implemented in this study, it is difficult to transition to complete carbide.

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Data
  • Wataru Zaitsu, Taihei Nagata
    2020 Volume 25 Issue 2 Pages 245-257
    Published: 2020
    Released on J-STAGE: July 31, 2020
    Advance online publication: April 27, 2020
    JOURNAL FREE ACCESS

     This study examined which factors influenced police officers' feeling of ease or difficulty while interviewing suspects. We conducted a self-administered questionnaire survey with police officers (N=183) who had experience in interviewing five or more suspects during the last decade. The questionnaire consisted of three components: (1) characteristics of police officers (five items, including gender, age, police officer rank, number of years that the police officers had engaged in criminal investigations, and the number of suspects the police officers had interviewed to date), (2) characteristics of suspects (52 items, including “foreign national”, “opposite sex”, “juvenile”, “rapid speaking”, and “compulsive liar”), and (3) circumstances of suspect interview (12 items, including “vicious crimes”, “sex crimes”, and “crime with an accomplice”). A total of 64 items for (2) characteristics of suspects and (3) circumstance of suspect interview were rated, using a seven-point Likert scale, by the police officers according to the degree of ease or difficulty while interviewing suspects. As a result, the police officers evaluated that 36 items (the suspect was a “foreign national”, a “compulsive liar”, and “finding faults”, etc.) made suspect interviews difficult, and 10 items (“full confession” and “existence of physical evidence”, etc.) made the interviews easy. If the suspect was accustomed to police interviews, the police officers' evaluations split into difficult and easy. Exploratory factor analysis extracted three factors from 19 items that were selected on the basis of factor loadings 0.40 and over: (1) the suspect's “self protection”, (2) the interviewer's “anxiety reduction”, and (3) “similar demographics” between interviewers and suspects. The “self protection” factor was found to have a significant positive correlation with number of years the police officers had engaged in criminal investigations. By contrast, each “anxiety reduction” and “similar demographics” factor demonstrated a significant negative correlation with them.

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