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1.
Anal Sci ; 34(6): 729-733, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29887563

RESUMO

Since fragments of concrete can be evidence of crime, a determination of whether or not they come from the same origin is required. The authors focused on nitric acid-soluble components in the fragments of concrete. As a result of qualitative analysis with ICP-MS, it was confirmed that elements such as Cu, Zn, Rb, Sr, Zr, Ba, La, Ce, Nd, and Pb were contained in the fragments. After the nitric acid-soluble components in the fragments of concrete were separated by dissolving them in nitric acid, the concentrations of these elements in the dissolved solution were quantitatively determined by ICP-MS. The concentration ratios of nine elements compared to La were used as indicators. By comparing these indicators, it was possible to discriminate between the fragments of concrete.

2.
Anal Sci ; 24(6): 745-9, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18544863

RESUMO

The effect of heating on the refractive index (RI) and trace elemental compositions of glass was investigated in order to develop an accurate discrimination method of glass fragments exposed to the high temperature of fire on illegal entrance into a crime scene for robbery. Fragments taken from 5 different sheet glasses were subjected to RI measurement and analysis of trace elements using ICP-MS before and after heating at 764 degrees C for 2 min. The difference in the RI between the heated and non-heated fragments ranged from 0.0012 to 0.0015, which corresponds to 6 times more than the variation of the RI within a pane of glass. In contrast, profiles of 10 elements (Co, Rb, Sr, Zr, Mo, Ba, La, Ce, Nd and Pb) in glass exhibited no significant difference between the heated and non-heated ones. In conclusion, the forensic discrimination of glass fragments must be performed not by RI measurement, but by analysis of the elemental compositions when glass evidence could be exposed to the high temperature of fire.

3.
Forensic Sci Int ; 175(2-3): 227-34, 2008 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-17764863

RESUMO

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.

4.
J Forensic Sci ; 50(4): 883-6, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16078492

RESUMO

In arson and bombing cases, matches are often used as the ignition method. We have investigated the use of elemental analysis by inductively coupled plasma-atomic emission spectrometry to discriminate match heads used in arson cases. Six elements, magnesium, aluminum, calcium, iron, zinc, and barium, in match heads were detected after the match heads were dissolved in HNO3, and these elements were quantified in 8 wood stick matches and 5 paper stick matches by means of calibration curves prepared from standard sample solutions. Using this method, we were able to distinguish all the matches from one another both before and after combustion. The method has the potential to be very useful for resolving arson cases.

5.
Anal Sci ; 21(7): 775-8, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16038493

RESUMO

Thirteen arsenous acid samples of known origins and refining methods were collected. Each sample was subjected to quantitative analysis of any impurity elements present using synchrotron radiation X-ray fluorescence spectrometry (SR-XRF) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). The trace elements selected were Sn, Sb and Bi for the reasons that they were considered not to be changed by their circumstances and that they showed high sensitivity to SR-XRF. These results obtained by both methods were compared and the correlation between these two methods was determined. The quantification of trace impurities obtained by SR-XRF using As as an internal standard showed good agreement with the results obtained by ICP-AES. The discrimination of refining method became possible by the comparison of these impurities' contents measured with non-destructive SR-XRF using several arsenous acid particles.

6.
Anal Sci ; 21(7): 785-7, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16038496

RESUMO

Small particles of gold foil detached from an indoor decoration might be important evidence to associate a suspect with a crime scene. We have investigated the application of elemental analysis using synchrotron radiation X-ray fluorescence spectrometry to discriminate small particles of gold foil. Eight kinds of gold foil samples collected in Japan were used in the experiments. As a result of synchrotron radiation X-ray fluorescence spectrometry, only two elements, gold and silver, were detected from all gold foil samples. The intensity ratios of AgKalpha/AuLalpha showed good correlation with the content ratios of Ag/Au. The variation of intensity ratio within a same sample was sufficiently small compared with those of different samples. Therefore the comparison of this intensity ratio can be an effective method to discriminate small particles originating from different types of gold foil.

7.
Anal Sci ; 21(7): 855-9, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16038509

RESUMO

Measurements of the refractive index (RI) and elemental analysis using synchrotron radiation X-ray fluorescence spectrometry (SR-XRF) were applied to the forensic discrimination of sheet-glass samples from different origins. The refractive index was calculated from the matching temperature at which the glass fragments became invisible in silicone oil. Fragments smaller than 1 mm in maximum diameter were taken from each of 11 sheet glasses and subjected to analysis by SR-XRF. The XRF spectrum of these samples indicated that a comparison of 6 elements (Ca, Fe, Sr, Zr, Ba and Ce) was useful for the discrimination of sheet glasses. Cluster analysis was performed using 33 sets of SR-XRF data obtained by triplicate measurements for the 11 glasses. Comparing 528 pairs among 33 samples, 515 pairs could be correctly discriminated. The number of indistinguishable pairs could be reduced from 36 to 4 by comparing the SR-XRF data. Elemental analysis by SR-XRF could provide small glass fragments with a more evidential value than the solely measurement of only RI, through a significant improvement of the discrimination capability.

8.
Forensic Sci Int ; 152(1): 29-34, 2005 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-15939173

RESUMO

5-(4-Nitrophenyl)-2,4-pentadien-1-al (NPPD) was used as a tracer by nonscientists at a simulated crime scene. A card with both a plastic-coated smooth surface and a porous cellulose matrix paper surface was coated with a methanol solution containing 0.5mg/mL of NPPD. The card was touched with bare fingers and fingers covered by a cotton glove. A color-change protocol was then used to detect the presence of NPPD. The bare fingers or the fingers of gloves were swabbed with a cotton swab, or the parts of the glove that had touched the card were cut out. The swabs or the cloth pieces were dipped in methanol, a 0.1% methanol solution of naphthoresorcinol was added, and then concentrated hydrochloric acid was added. The observation of a red color at this point indicated a positive test. NPPD was easily observed in the experiments involving bare fingers, but no color change was observed from the swabbing of the cotton glove. However, when the cloth pieces cut from the fingers of the glove were subjected to the test, the red color was observed. In an attempt to enhance the sensitivity of the test, the volumes of the reagent solutions were reduced, but no improvement in sensitivity was obtained.

9.
Forensic Sci Int ; 148(1): 55-9, 2005 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-15607590

RESUMO

In the poisonous incident case occurred in Japan, clarification of the identity between seized poisons and retrieved from crime scene is strictly required from the court. In this case, arsenous acid was used as a poisonous material and, seized one from suspect's house was only twenty particles. The synchrotron X-ray fluorescence spectrometry by comparing the intensity ratios of L(alpha) line of four heavy metal, such as Bi, Sn, Sb, Se to K(beta) line of As was performed to overcome this problem. In this paper, the evaluation of this new method using 13 authentic arsenous acid samples, 4 of 13 were refined by Chinese method, 7 of 13 were refined by Japanese method (Sumitomo mining Co. Ltd. method), 2 of 13 were refined by German and Swiss method. As a result, by the comparison of the ratios of these four elements to As, these 13 samples were clearly classified to three products classes produced by different refining methods.

10.
J Forensic Sci ; 49(3): 517-22, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15171169

RESUMO

The chemical compound 5-(4-nitrophenyl)-2,4-pentadien-1-al (NPPD), called "spy dust," was used in the Soviet Union as a shadowing pursuit, the act of following someone secretly, for investigating the activities of diplomatic personnel. It is also useful for counter-terrorism, and some criminal cases in the forensic science field. In this paper, it was synthesized and evaluated as a tracer for shadowing pursuits. The method for utilizing this reagent was very simple: it was dissolved in methanol (1 mg/mL) and sprayed on the restricted area. If the suspect was to enter this area or touched the sprayed material, NPPD was attached to the suspect's shoe surface or hands. The color examination was a two-steps process: first was the addition of 1 mL of a 0.1% naphthoresorcinol methanol solution to the methanol extracts of a methanol-contained cotton swab used to smear some surfaces of the suspect, and second, the addition of 1 mL of concentrated hydrochloric acid, which turned the solution dark red. The gamma max of the colored solution was 510 nm, measured by ultraviolet-vis spectroscopy. Detection limits for three methods were determined: a visual method (detection limit 100 ng/3 mL), an ultraviolet-visible spectrometric method (detection limit 10 ng/3 mL), and a selected-ion-monitoring gas chromatographic/mass spectrometric method (detection limit 300 pg/injection). The forensic utility of NPPD was demonstrated for two simulated cases: a theft case and a case where NPPD was used as a tracer to prove that an automobile had entered a restricted area. These examinations prove NPPD is a useful shadowing pursuit (spy dust) for the forensic science field.


Assuntos
Medicina Legal/métodos , Nitrobenzenos/química , Cromatografia Gasosa , Humanos , Ácido Clorídrico , Espectrometria de Massas , Metanol , Estrutura Molecular , Naftóis , Solventes , Espectrofotometria Ultravioleta
11.
Anal Sci ; 19(3): 415-8, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12675351

RESUMO

Trace impurities in lead-tin solders were determined using inductively coupled plasma atomic emission spectrometry (ICP-AES) for the forensic discrimination of solder samples from different origins by a comparison of the concentration for each element. After about 10 mg of sample was accurately measured and taken into a glass tube, 1 ml of HNO3 was added. The tube was capped and heated at 80 degrees C for 10 min. After cooling to the room temperature, 1 ml of HCl and 2 ml of purified water were added. It was then agitated until the sample was completely dissolved, followed by dilution to 10 ml. Five elements (Sb, Bi, Cu, As and Ag) in this solution were determined by ICP-AES. The observed values for these elements in the NIST Standard Reference Material 1131 showed good agreement with the certified ones. Eighteen kinds of solder samples could be distinguished from each other, since all of the pairs among these samples provided remarkable difference in the concentration of the trace elements. The copper concentration should have been excluded from the comparison when it increased after melting by a soldering iron made of copper.

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