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ENFSI Proficiency Test on Identification of GSR by SEM/EDX

- GSR2003 -

(European Union Project No. JAI/2001/OIS/059)

Instructions

Dear colleagues,

enclosed you will find your sample for the ENFSI Proficiency Test on GSR (GSR2003). Please examine it, as far as feasible, according to your standard laboratory procedure for GSR analysis.

The proceeding of the ENFSI Proficiency Test GSR2003 will be performed in the same way as in the previous tests. Lab-code numbers have been assigned to all participating laboratories in order to maintain confidentiality. After the evaluation of the test each laboratory will be informed immediately about its findings in an individual report. The results compiled from this program will be presented and discussed at the final meeting in November 2003, where a detailed report is circulated as well.

The ENFSI Proficiency Test GSR2003 consists again of a synthetic particle sample which shows all the criteria demanded in proficiency testing (in particular: identical sample material and homogeneity of sample sets). That means there is a certain amount of synthetic GSR particles consisting of Pb, Sb and Ba on each sample with well-defined size and location. The composition of the particles as well as location and size are exactly known by the organiser.

All participants are supposed to search for artificial Lead/Barium/Antimony/Barium particles on the test samples representing unique GSR particles.

For additional information regarding the recent state of affairs you are requested to check the QUO DATA website www.quodata.de/GSR2003.html, where all further and current documents have been provided for download as well.

Sample Description

You will find enclosed your sample of the ENFSI Proficiency Test GSR2003, assigned with a Lab-Code on the plastic cover of the stub which correlates to the unique numbering of your sample located on the bottom left part of the sample. If somehow possible please examine the samples according to your default SEM/EDX settings. If there is a change of parameter settings necessary to run the samples, please note that in the comments of your data report file.

The sample shows the following properties:

A silicon chip of 8x8 mm² is mounted on a standard 1/2-inch stub. On this chip there is an area of 7x7 mm² where an exactly defined number of PbBaSbBa particles is distributed. (In fact the composition of the "GSR particles" is Pb, Ba,Sb, Ba, and and F. The F-signal results from the BaF2 that was used in the sample preparation process.) The PbSbBa particles have to be searched and filed.

The sample is almost free of "contamination" for reasons of a standard for fast verification purposes in future applications. For protective reasons the chip has finally been coated with a thin carbon layer, which is supposed to avoid charging. Nevertheless, if charging occurs, you are recommended to perform a supplementary carbon coating of the sample.

Mount the test sample on your stage in a way that the small 100x100 µm² pad is displayed in the lower left corner of your SEM screen, and examine at least the centre area of 7x7mm² of the chip (see Fig.1).

If the BSE threshold adjustment has to be changed compared to your standard settings, it is recommend-ed to use the 100x100µm² pad or the 10µm PbSbBa particle, the latter located exactly in the center of the chip (4000;4000), for a suitable BSE adjustment.

Due to a 10µm thick carbon coating as intermediate layer on the silicon substrate, no disturbing silicon line in the EDX spectrum should occur.


Although, if an interfering Si-signal in the obtained spectra is leading to a false classification of the PbSbBa particles, it is recommended to either add Silicon as a matrix element in your criteria list or set the Si-signal to zero. Please note any of these necessary changes of the standard settings as a comment in your data sheets.

If there are particles put into the PbSb, PbBa or SbBa class, please report them as well.

Data Reporting

You have to submit your obtained data (raw data) in the prepared EXCEL file (Appendix1.xls) which is to be found on the attached floppy disk. Please report your raw particle data and if available your evaluated data in absolute X and Y co-ordinates (in µm or mm) and the corresponding particle sizes (calculated diameter). Data which are obtained by manual search will not be considered in the final report. In addition you have to fill in Appendix2.doc to record the instrumental/procedural conditions of your search and general information concerning GSR casework.

Submission of data may be performed either electronically by email or by sending back the disk by postal mail with reference to your lab-code ID. Mailing addresses are:

email:

or

postal mail: Dr. L. Niewoehner

BKA; KT23

D-65173 Wiesbaden

GERMANY

Deadline

Results that are labelled with your lab-code ID must be received (at least in electronic form) by the organiser bybefore July July 15th 2003 and labelled with your lab code in order to be evaluated and considered in the final report.

Lab-Code

Your lab-code is mentioned on the blue transport box and on the sample container. When submitting your data and questionnaire, please refer all your documents to this lab-code.

Bundeskriminalamt - KT23
Thaerstraße 11
D-65193 Wiesbaden / Phone
+49 611 55-1 2678 / Fax
+49 611 55-4 5087 / e-mail