Forensic laboratory

One of the particulady challenging aspects of the work in a museum laboratory is the enormous variety of problems encountered. Every object examined is unique and for each the questions to be answered differ. Thus the museum laboratory most closely resembles, if anything, the forensic laboratory, and many of the methodologies employed are common (see Forensic chemistry). 

Eorensic science laboratories may have different missions and therefore conduct different types of testing on samples (21,22). Eor example, the United States Department of Justice, Dmg Enforcement Administration (DEA) forensic laboratories assist authorities ia criminal intelligence-gathering efforts. As such, DEA chemists routinely analyze both the iUicit dmg and excipient, the material used ia the cutting or diluting of the pure dmg, ia a given specimen. The excipient may provide information as to where the sample was produced. 

Local and state forensic laboratories generally do not engage ia excipient testing. Most provide quaUtative and quantitative analysis of the evidence to determine if an Ulegal substance is present and if so, the amount of the dmg present. The quantity of dmg seized by the authorities may be important ia jurisdictions which give enhanced sentences for larger amounts of the pure dmg, or ia some cases the total weight on the dmg and diluent ia possession of the defendant. 

For use in criminal cases, forensic laboratories in the United States have agreed on 13 core STR loci that are most accurate for identification of an individual. Based on these 13 loci, a Combined DNA Index System (CODTS) has... 

Because the scent of a flower may be due to hundreds of different compounds, it is difficult for perfume manufacturers to duplicate floral scents. Establishing the identities and relative amounts of the components of a fragrance was actually impossible until the development of chromatography. Related techniques are used in forensic laboratories to match samples of fluids, by food manufacturers to test product quality, and to search for evidence of life on other planets. All these techniques depend on subtle differences in intermolecular forces to separate compounds. 

Laboratory Manual, SE/TE Forensics Laboratory Manual, SE/TE CBL Laboratory Manual, SE/TE Small-Scale Laboratory Manual, SE/TE ChemLab and MiniLab Worksheets... 

The accurate analysis of these substances is the responsibility of the Drug Enforcement Administration s forensic laboratory system. This system consists of six regional laboratories - in New York, Chicago, San Francisco, Dallas, and Washington, D.C. - together with a special testing and research center in McLean, Virginia. 

Foreign uranium resources, 17 522 Foreman and Veatch cell, 9 664 Forensic analysts, certification of, 12 95 Forensic biology, 12 102-104 Forensic chemistry, 12 89-104 physical evidence in, 12 90-95 Forensic laboratories, local and state, 12 98 Forensics, liquid chromatography applications, 6 465 Forensic science laboratories, 12 95 Forensic science, supercritical fluid extraction in, 24 14 Forensic testing, 12 95-104 Forensic toxicology, interpretation of results in, 12 98... 

Analysis of small ions has been published for many applications other than pharmaceutical applications, and has a growing impact in industrial, environmental, biomedical, clinical, and forensic laboratories. Sample matrices range from simple tap water to Kraft black liquor, including river and seawater, beer and wine, environmental water, and nuclear plant water, but also body fluids such as serum, urine, plasma, cerebrospinal fluid, and many others. Those topics alone would require a separate book. 

The main drawback of the use of color reactions for the analysis of explosives lies in their often low specificity. Although their specificity varies according to the type of reactions - and some reactions are quite specific - it is generally not safe enough to establish an identification of an explosive in a forensic laboratory on color reactions alone. When the color is obtained, the key question is whether other compounds, which are not explosives, can produce the same color under identical experimental conditions. Unfortunately, the answer is usually, yes. Thus, in forensic analysis, where an erroneous identification may lead to a gross injustice, it is generally accepted that the identification of an explosive should not depend on color reactions alone. 

Reliable identification of explosives in a modem forensic laboratory is based on instmmental techniques, mainly spectrometric, often in conjunction with chromatographic methods. Gas chromatography—mass spectrometry (GC/MS) is considered to be an excellent and reliable method in forensic analysis, including the analysis of explosives. 

In forensic laboratories, chemical spot tests based on color reactions, have been replaced over the years by modem, more accurate instrumental methods. However, analytical techniques based on color formation are stiU commonly employed in field tests for explosives. Being inexpensive, simple, easy-to-operate and often quite sensitive (see above), they are most suitable for use outside the laboratory as presumptive field tests for the presence of explosives. 

Ion mobility spectrometry (IMS) is in worldwide, daily use in laboratories in many fields of chemistry, medicine, food science, and manufacturing and is perhaps the most commonly used technology for detection of explosives at the present time. Its use in forensic laboratories is well known. In fact, it is so well established that there is a journal specializing in IMS [1], A recent book... 

Lawrence Kobilinsky, Ph.D., is a professor of biology and immunology at the City University of New York John Jay College of Criminal Justice. He currently serves as science advisor to the college s president and is also a member of the doctoral faculties of biochemistry and criminal justice of the CUNY Graduate Center. He is an advisor to forensic laboratories around the world and serves as a consultant to attorneys on major crime issues related to DNA analysis and crime scene investigation. 

The DNA fingerprinting technique has now been applied almost routinely in all modem forensic laboratories to solve various crimes. When a DNA... 

I hope that this book will be of interest to everyone involved with HEMs irrespective of their background R D laboratories, universities and institutes, production agencies, quality assurance agencies, homeland security, forensic laboratories, chemical industries and armed forces (army, navy and air force). This book will also be of immense use to organizations dealing with the production of commercial explosives and allied chemicals. 

Such results have been used to both convict and acquit suspects and, in other cases, to establish paternity with an extraordinary degree of certainty. The impact of these procedures on court cases will continue to grow as societies agree on the standards and as formal methods become widely established in forensic laboratories. Even decades-old murder mysteries... 

Titration is one of the universal techniques of chemistry and is commonly used to determine the concentration of a solute. Titrations may be either acid-base titrations, in which an acid reacts with a base, or redox titrations, in which the reaction is between a reducing agent and an oxidizing agent. Here we concentrate on acid-base titrations. The technique is used in research laboratories, hospitals, and industry to determine the amounts of acid and base in solutions. It is also used in forensic laboratories and for monitoring the environment. 

Forensic laboratories in the United States have agreed on 13 core STR loci that are most accurate for identification of an individual. Based on these 13 loci, a Combined DNA Index System (CODIS) has been established to serve as a registry of convicted offenders. If the profile of sequences from a known individual and the profile from DNA obtained at a crime scene match, the probability is approximately 82 billion to 1 that the DNA is from the same individual. In paternity cases, where the DNA of father and offspring are related but not fully identical, the identity of the father can be established with a probability of 100,000 to 1. 

Urine analysis for illegal drugs is increasingly performed in forensic laboratories (especially in Japan). Gas chromatography-mass spectrometry (GC-MS) is extensively used because of its versatility and reliability. By way of sample preparation for GC analysis, conventional liquid-liquid extraction has a widespread use, but it is not only laborious but also environmentally unfriendly due to the consumption of considerable amounts of organic solvents. Therefore, microintegration of the sample preparation procedure is required. 

Quality management and accreditation have become matters of increasing relevance in analytical toxicology in recent years. Forensic laboratory accreditation is based upon international standards (ISO/IEC 17025 2005 [68]) which include requirements for method validation and allows to control and monitor overtime the laboratory performance and its analysts by proficiency tests [69],... 

The need to staff forensic laboratories with qualified personnel has created a demand for education facilities to prepare forensic scientists. Educators in colleges and universities in many parts of the country are responding to this demand. Very quickly these brave souls discover that being an educator in forensic science places them directly in the middle of a controversy in which the educational needs of the forensic science profession must be placed in a frame work prescribed by college or university administration. At this point, the educator becomes the man in the middle. To survive this controversy, the educator must recognize each problem area and somehow reach a solution acceptable to the parties involved. 

Concerning the internship itself, students take nearly all of their science, law, and forensic science courses prior to the internship. With this background, students should be able to function in the forensic laboratory without disrupting normal laboratory operations. The potential burden that massive student internship programs could place on already overtaxed forensic laboratory facilities may discourage some forensic laboratory participation. Precautions must be taken to insure against this abuse, since the student internship is essential to the production of quality personnel. 

Table II presents a specimen program of the full-time M.S. degree in forensic chemistry at Northeastern which requires 1-1/4 years for completion. Part-time students take a comparable program however, a slower pace is typically selected, with 2-1/4 to 3-1/4 years required for completion. The program is primarily designed to offer a terminal degree for students seeking immediate forensic laboratory employment and secondarily to serve as a source of qualified applicants for a Ph.D. degree in forensic chemistry (see later). While it is not possible to discuss in depth all the courses, it is appropriate to overview the program. (Further details can be obtained by writing to Dr. B.L. Karger or J. M. Parker.)...

The course on crime scene investigation will be offered by the College of Criminal Justice and will emphasize the importance of scene examination and evidence sampling. An improper sampling method can invalidate the results of the forensic laboratory. 

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