Elemental Analysis of Forensic Evidence with Focus on Interpretation of the Evidence

Transcription

1 Elemental Analysis of Forensic Evidence with Focus on Interpretation of the Evidence December 5 th 9 th 2011 Instructors/Facilitators: Tatiana Trejos, MSFS - FIU José R. Almirall, PhD - FIU Florida International University Department of Chemistry and Biochemistry and International Forensic Research Institute

2 PROGRAM AIMS This workshop/working group session is designed to provide advanced training and an opportunity for information exchange between experienced forensic scientists who currently perform elemental analysis of trace evidence by any of a variety of methods. The focus of the weeklong program will be placed on the interpretation of the data generated from the analysis. Learning Objectives: Upon completion of this workshop the participants will be able to understand and review the basic principles and practical aspects of the application of different techniques for forensic elemental analysis of trace evidence. The workshop will cover the following; XRF, SEM-EDS, ICP-MS, LA-ICP- MS and LIBS. The participants will be able to conduct a critical evaluation of the limitations and capabilities of these techniques, including sampling procedures, sample preparation methods, quality control, data analysis and interpretation of results. Lectures will include a review of the fundamentals of the above techniques and their application to the analysis of different trace evidence such as glass, paint, soil and biological matrices. As part of the learning experience, the attendees will participate in two round robin analysis of both glass samples and standards. The first round robin will be completed before the workshop, the second will be completed after the workshop. The attendees will participate in the analysis, statistical data treatment, interpretation and discussion of results. Target audience: The target audience for this session are practicing forensic scientists and researchers that currently have access to either XRF, ICP-AES, ICP-MS and/or LA-ICP-MS for the elemental analysis of trace evidence. Instructors: José R. Almirall, PhD, Department of Chemistry and Biochemistry and International Forensic Research Institute, Florida International University Tatiana Trejos, MSFS, Department of Chemistry and Biochemistry and International Forensic Research Institute, Florida International University

3 DAY am Registration and Coffee (CP 153) am Welcome and Introduction am Introduction to variations in trace elemental composition in nature and in man-made materials am Introduction to the principles of SEM-EDS and X-Ray Fluorescence (XRF) for the forensic analysis of materials Coffee/Tea Break am Introduction to the principles and new developments in the application of elemental analysis by Inductively Coupled Plasma Spectrometry (ICP-MS) and Laser Ablation (LA) Sampling for ICP-MS analysis of materials pm Discussion pm Tour to Trace Evidence Analysis Facility and Lunch Break pm Trace Elemental Analysis of Glass How does glass as a matrix differ from other materials encountered in the forensic laboratory The NITECRIME experience pm Examples of casework analysis of glass using LA-ICP-MS and XRF with focus on interpretation and report wording pm Elemental Analysis of other matrices (Paint, Soils, Inks, Biological matrices) pm Coffee/Tea Break pm Instrumental Considerations in SEM-EDS, XRF, LIBS and LAICPMS. 4: pm New challenges to evidence analysis- a discussion of future directions in elemental analysis with focus on match criteria and interpretation of evidence 6:30 pm Workshop Dinner DAY pm Laboratory exercises (LAICPMS and XRF, Laboratory #1, 2 and 3) at OE 109 Case studies with focus on interpretation of results

4 DAY 3 (All groups together) am Statistical analysis of elemental data- part 1 (Introduction) am Statistical analysis of elemental data part 2 (Multivariate) am Statistical analysis of elemental data part 3 (Match Criteria, am Presentation and discussion of results of Round Robin studies pm Lunch Break pm LA-ICP-MS data analysis, interpretation and reporting pm XRF data analysis, interpretation and reporting pm Discussion on interpretation of trace evidence and match criteria pm Statistical analysis and match criteria - Exercises DAY Introduction to LIBS and glass analysis by LIBS Laboratory Exercises (LIBS, Laboratory #4) at CP Statistical analysis and match criteria exercises pm Lunch Break 1.30pm 5.00pm Interpretation of Results and group discussions (all groups together) DAY 5 8: Data presentation by all groups. Report writing and testimony on elemental analysis of forensic samples 11:00-12:00 Workshop/Working Group Exam and session evaluation

5 LABORATORY EXERCISES: The class will be divided into 3 groups (Group A, Group B and Group C). Each participant can choose to do full day laboratory exercises in a single technique LAICPMS or XRF, or do half-day practices on each one, according to their expertise and interests. Attendees in all 3 groups will participate together in the data analysis and data presentation exercises. Distribution of group practices: Group Tuesday (all day) OE 109 A Lab 1 LA-ICPMS (Quadrupole) Description Morning session: instrument familiarization, tuning and optimization of the LA system and the ELAN quadrupole ICPMS. Afternoon session: analysis of samples and standards following NITECRIME protocol B Lab 2 Data interpretation and match criteria C Lab 3 XRF Morning session: statistical analysis and match criteria exercises Afternoon session: statistical analysis and match criteria exercises Morning session: instrument familiarization, optimization of the system and beginning of data acquisition Afternoon session: continue with analysis of samples and standards