Forensic Application_of_XRF

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X-ray fluorescence spectroscopy is non-destructive. Spectral positions are almost independent of the chemical state of the analytical

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Dr. Shailendra Jha and Dr. Mukesh Sharma Physics Division State Forensic Science Laboratory, Jaipur E-mail : mksphy@gmail.com Advanced Non-Destructive X-rays Techniques in Forensic Examination of Metallic Articles: Some Cases Study

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29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur Contents Introduction : What is X-rays fluorescence ? Instrument : X-rays Set-up (Installed at Physics Division) Methodology Our case study Results and conclusion

X-Ray Fluorescence : How does it work?:

29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur X-Ray Fluorescence : How does it work? Incident X-rays strike sample Excitation of characteristics X-ray fluorescence Element of specific characteristic radiation is detected Software evaluates spectrum

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29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur X-rays Set-up: Methodology

K & L Spectral Lines:

29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur K & L Spectral Lines K - alpha lines: L shell e- transition to fill a vacancy in K shell. Most frequent transition, hence most intense peak. K - beta lines: M shell e-transitions to fill a vacancy in K shell. L - alpha lines: M shell e- transition to fill a vacancy in L shell. L - beta lines: N shell e- transition to fill a vacancy in L shell. L Shell K Shell K alpha K beta M Shell L alpha N Shell L beta

X-Ray Fluorescence Spectrometry  Advantages:

29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur X-Ray Fluorescence Spectrometry  Advantages X-ray spectra is simple and regular X-ray fluorescence spectroscopy is non-destructive Spectral positions are almost independent of the chemical state of the analytical Minimal sample preparation Applicable over a wide range of concentrations

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29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur Our Case study : Case I: Testing of Purity of Indian Ornaments : Very interesting case sample was analyzed using WD-XRF.In this case one road side jeweler have cheated one house wife by selling her four fake golden ornaments at her home. These exhibits were examined and results are interpreted in terms of the composition of the elements. Contribution to the Forensic Community by these study: 1. To provide systematic approach to examine XRF 2. Different methodology have been used to construct composition of ornaments in India, which may lead non-homogeneity. 3. In all three cases are different in nature, interesting and overall very useful for forensic community in terms of final examination report.

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29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur Element Exhibit –A Exhibit –B Exhibit –C Exhibit –D Ni 82.5548 % 95.5102% 94.6890% 74.3267% Cu 9.1711 % --- --- 14.5028% Na 1.7328 % 1.0163% 1.7924% 1.0963% Si 1.4121 % 0.4824% 0.7038% 1.5094% Au 1.4072 % 1.6210% 1.0725% 1.8018% Mg 0.8803 % 0.3289% 0.4635% 1.0821% Cl 0.8777 % 0.1773% 0.4343% 0.6929% Zn 0.6169 % 0.1465% 0.2310% 0.6162% Al 0.4896 % 0.1423% 0.1623% 0.4482% Ca 0.2982 % 0.0867% 0.1168% 0.3312% S 0.1835 % 0.0383% 0.1143% 0.2016% Results of four different Indian Jewellery exhibits in terms of elemental composition

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29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur RESULTS - Case I: In this case four Indian ornaments made of gold (as said) have been examined. Very interesting results were drawn that in all four exhibits. The elemental composition was not similar in terms of percentages or number of elements. All the ornaments mostly containing 74 – 94 % Ni and Cu. Surfaces of these ornaments were coated with the very thin gold layer as per the XRF measurement percentage of Au in all exhibits were only 1 ~ 2 %.

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29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur Case II: Fake Silver Brick : In this case, a jeweller was cheated by two people. Those had supplied him a fake silver brick having 15.4 cm x 13.2 cm x 3.9 cm dimensions, quoting that the brick is made of 80 to 85 % of silver. After purchasing this by an amount of 1.5 million Indian rupees, he doubted that the brick was fake and the persons, who had sold him the brick, were fraud. So, he lodged a complaint against them in police station.

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29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur Case study I: In this case a brick of fake Silver is being sent for examination with the questionnaires : - Q. 1 How much part of this brick is pure, percentage of the purity? Q. 2. How many other elements are present in this brick? Q. 3 Is there any impurity in the brick?

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29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur Case study : Fake silver brick:- Exhibit -A marked as exhibit A/1 marked as exhibit A/2 marked as exhibit A/3 s-1 s-2 s-1 s-2 s-1 s-2 Shape : - Rectangular; Length : 15.4 Cm (approx.); Width : - 11.5 Cm (approx.); Height : 3.9 Cm (approx.)

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29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur Sample : PHY-414-06EX-A-1 ( For all surfaces) Group : [Quantitative/ Qualitative] New Group Date : 2009-02-13 01:07:10 [Measurement Condition] : Aperture:3.0 mm Atmosphere: Vac. Spin: On Analyte TG kV mA Fl Slit Detector Angle Time (in Sec) -------------------------------------------------------------------------------------------------------- ====[Bulk]============================================================= Ag Rh 40 95 -- Std Off LiF SC 25- 75 P- 2BG 16.010 40 Zn Rh 40 95 -- Std Off LiF SC 25- 75 P- 2BG 41.800 40 Sn Rh 40 95 -- Std Off LiF FPC 25- 75 P- 2BG 126.760 40 Cu Rh 40 95 -- Std Off LiF SC 25- 75 P- 2BG 45.030 40 Pb Rh 40 95 -- Std Off LiF SC 25- 75 P- 2BG 28.260 40 Au Rh 40 95 -- Std Off LiF SC 25- 75 P- 2BG 36.960 40 Al Rh 40 95 -- Std Off PET FPC 25- 75 P- 2BG 144.580 40 Measuring Parameters:

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29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur Table of the results of examination: This analysis is being computed with the help of program provided with the set-up and can also be computed using theoretical model calculations : Fundamental parameter method Exhibit Name Elements present (in %) Ag Zn Sn Cu Pb Au Al Exhibit A/1 s-1 76.35 14.55 0.02 8.91 0.0 0.0 0.14 s-2 0.58 27.21 0.14 71.50 0.06 0.0 0.49 Exhibit A/2 s-1 75.67 14.64 0.09 9.36 0.0 0.0 0.19 s-2 0.82 27.59 0.12 70.95 0.06 0.0 0.45 Exhibit A /3 s-1 75.29 14.71 0.04 9.72 0.0 0.0 0.15 s-2 0.32 27.38 0.12 71.84 0.05 0.0 0.27 Case study

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29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur Pure silver surface with the thickness of 3 mm surrounding Cavities made of Cu, Zn and Sn

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29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur Results of examination Case II: Spot test is not applicable in this type of cases (percentage of elements only). The exhibit A is not 100% pure. It contain 70-75 % silver at it surfaces about 3 mm all around. The exhibit A having impurity like Cu, Zn & Sn and very small amount of Pb and Al also in it.

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29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur Case III: Reconstruction of Stolen Idol : A priest of a temple lodged a case that someone had stolen temple’s idol namely “RAM DARBAR” contained Ram, Sita, Laxman and Hanuman’s idols on one base. The idol was made of pure silver having weight about 6 Kg. The investigating officer have caught six people and collected all the pieces which they have distributed equal in weight among them by cutting the idol using hammer and hacksaw. All collected pieces have been forwarded in the Laboratory for examination. The samples were analyzed using WD-XRF.

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29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur Exhibit Name Elemental composition in Percentage Ag Zn Sn Ni Cu Exhibit–A 97.769 0.064 0.000 0.012 2.156 Exhibit–B 96.742 0.136 0.027 0.013 3.080 Exhibit–C 97.103 0.103 0.059 0.060 1.928 Exhibit–D 98.312 0.105 0.000 0.021 1.562 Exhibit-E 98.839 0.066 0.035 0.009 2.052 Exhibit-F 98.216 0.024 0.000 0.618 1.143

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29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur Results of Examination Case III: From Table, it is clear that the pieces maximum amount of silver say about 96.7% to 98.9%. These exhibits showing the other elements like Zn, Sn, Ni and Cu were in traces. One can conclude that these exhibit having approximately same amount of impurity in terms percentages (2-3%) with similar elements like Zn, Sn, Ni and Cu which verify the possibility that all the pieces were recovered from the different people belongs to one idol and made it one idol of Lord Shree Ram Darbar.

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29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur It is important to note, in Indian context, that a number of different techniques are used to fabricate jewellery, ornaments which results in samples that vary considerably in homogeneity, and hence their suitability for accurate XRF analysis. Lost wax investment casting, extrusion - rolling - stamping, pressed powder, and electroforming processes are all used to design jewellery/ornaments. XRF is essentially a surface analysis technique with an effective depth of approximately 10um for typical jewellery alloys, it is possible for ‘sample - prep’ errors to be introduced into the measurement due to heterogeneity Conclusions

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29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur Acknowledgement Research Advisors: Rt. Prof. B K Sharma, UOR, Jaipur Prof. B L Ahuja, MLSU, Udaipur Prof. R. Dovesi, TU Turin, Italy

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29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur References: 1. Introduction to X-Ray Spectrometry K. L. Williams, 1987 Allen & Unwin (covers both XRF and EPMA) 2. X-Rays, Electrons, and Analytical Chemistry Liebhafsky, Pfeiffer, Winslow and Zemany, 1972, Wiley 3. Elements of Modern X-Ray Physics Als-Nielsen and McMorrow, 2001, Wiley 4. H. Ida and J. Kawai, Anal. Bioanal. Chem 379, 735 (2004); also H. Ida and J. Kawai, Anal. Sciences 20, 1211 (2004). 5. W. Kugler Ad. in X-ray Analysis 46, 1 (2003). 6. M. Mialazzo, Nucl. Inst. and Methds. Phys. Res. B213, 683 (2004).

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29-Sep-12 Dr. Mukesh Sharma SFSL, Jaipur Thank you for your kind attention

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