DEPARTMENT OF CHEMISTRY AND BIOCHEMISTRY AND INTERNATIONAL FORENSIC RESEARCH INSTITUTE
Florida International University, University Park, Miami, Florida 33199

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Developing Of A Standardized Field Portable Extraction Gas Chromatography Tandem Mass Spectrometry For The Analysis Of Ignitable Liquid Residues

By: Marilyn Prieto, B.S. Candidate in Chemistry

The discovery and assimilation of small amounts of Ignitable Liquid Residues (ILR) in fire debris evidence can be difficult because of the considerable loss of these compounds during the fire, extraction techniques that are not the most sensitive, co-extraction of interfering products (IP), and analysis techniques that provide low discrimination. The main purpose of my project was to optimize a general method that can be used by examiners to improve current analysis of fire debris without significantly altering the workload or time required for analysis.  Hopefully, the method that is created will increase the sensitivity and selectivity that is necessary to detect minute amounts of ILR remaining after a fire and to differentiate ILR from IP. It is anticipated that the results using GC/IT/MS/MS will not require sophisticated training, longer analysis times, or data analysis programs.

Using Laser Induced Breakdown Spectroscopy (LIBS) For Elemental Analysis Of Matrices Of Forensic Interest

By: Marilyn Prieto, B.S. Candidate in Chemistry

Elemental analyses within matrices of forensic interest such as glass, paint, fibers, gunshot residues, etc. are of extreme importance in the forensic field.  LIBS is a technique which already has a wide variety of practical applications in several realms of science and industry, but is new to the forensic science arena.   The advantages of LIBS is that it is virtually non-destructive, requires little or no sample preparation, user friendly, affordable, provides good detection limits (~50 ppm), offers qualitative analysis, and has the potential for portability.  LIBS uses a laser beam to induce breakdown in the target material.  This breakdown consequently results in an emission that can be spectroscopically analyzed.  I am attempting to observe whether this technique may be utilized as a quantitative tool for the target materials named above.  It is imperative that a fast and efficient method for those materials exist due to the increasing number of traffic accidents occurring in the United States today.

Plasma Shadowgraphy as Diagnostic for Laser Induced Breakdown Spectroscopy

By: María Pérez, B.S. Candidate in Chemistry

The aim of this research project is to build and use an imaging system to monitor the plasma evolution during Laser Induced Breakdown Spectroscopy experiments. It involves the use of a pulsed Nd:YAG laser at different wavelengths used to generate a laser induced plasma so that the evolution of the plasma can be visualized with shadowgraphy in order to monitor the plasma characteristics over its lifetime. Different parameters such as laser wavelength and atmospheric conditions over the plasma will be varied parameters for these experiments.

Precise Deposition of Known Mass Loadings of Low Quantities of Explosives on Surfaces

By: Yisenny Delgado, B.S. Candidate in Chemistry

Making standards with known loadings and characterizing them with The FT-Raman and GC-MS. The FT- 2800 and the GC Varian 3800 are used to know the quality of printed standards. Drugs and explosives such as Cocaine, Amphetamines, RDX, and TNT are the analytes of choice.