Forensic toxicology is the use of toxicology and other disciplines such as analytical chemistry, pharmacology and clinical chemistry to aid medicolegal investigation of death, poisoning, and drug use. The primary concern for forensic toxicology is not the legal outcome of the toxicological investigation, but rather the technology and techniques for obtaining and interpreting the results. A toxicological analysis can be done to various kinds of samples. Download high resolution version (1760x1164, 1116 KB)Public domain. ... Forensics redirects here. ... This article needs additional references or sources for verification. ... Forensic dentistry or forensic odontology, the proper handling, examination and evaluation of dental evidence, which will be then presented in the interest of justice. ... Forensic anthropology is the application of the science of physical anthropology and human osteology (the study of the human skeleton) in a legal setting, most often in criminal cases where the victims remains are more or less skeletonized. ... Forensic entomology is the science and study of insects and other arthropods related to legal investigations. ... This article or section does not cite any references or sources. ... Forensic psychiatry is a subspeciality of psychiatry. ... A macro shot of a palm and the base of several fingers; as seen here, debris can gather between the ridges. ... Forensic accounting is the specialty practice area of accounting that describes engagements that result from actual or anticipated disputes or litigation. ... Ballistics (gr. ... Bloodstain pattern analysis (BPA) is one of several specialties in the field of forensic science. ... Forensic genetics refers to the application of genetic science to legal matters. ... Forensic footwear evidence can be used in legal proceedings to help prove the identities of persons at the crime scene. ... Questioned document examination (QDE) is known by many names including forensic document examination, document examination, diplomatics, handwriting examination, and sometimes handwriting analysis, although the latter name is not often used as it may be confused with graphology. ... Preparing C-4 explosive This article is concerned solely with chemical explosives. ... Information Forensics is the science of investigation into systemic processes that produce information. ... The simple definition of computer forensics - Chris L.T. Brown, Computer Evidence Collection and Preservation, 2006 Thus, it is more than the technological, systematic inspection of the computer system and its contents for evidence or supportive evidence of a civil wrong or a criminal act. ... Forensic engineering is the investigation of materials, products, structures or components that fail or do not operate/function as intended, causing personal injury for example. ... Fire investigation, sometimes referred to as origin and cause investigation, is the analysis of fire-related incidents. ... Vehicular accident reconstructions are often conducted by specialized units in law enforcement agencies, to answer questions about automobile accidents, such as who was driving, where were the victims seated, were they using seat belts? Through accident reconstruction, rigorous analysis is done, with expert witnesses that can present results in trial. ... Dr. Edmond Locard (1877-1966) was a pioneer in forensic science who became known as the Sherlock Holmes of France. ... Dr. William M. Bass is a U.S. forensic anthropologist, renowned for his research on human osteology and human decomposition. ... A crime scene is a location where an illegal act took place such as molestation, rape or illegal turnip smoking, and comprises the area from which most of the physical evidence is retrieved by [[forensics|forensic scientists] for example the reknowned criminal investigator and skilled forensic scientist, who is unfortunately... The CSI Effect (sometimes referred to as the CSI syndrome) is a reference to the phenomenon of popular television shows such as the CSI franchise, the Law & Order Franchise and Crossing Jordan raising crime victims and jury members real-world expectations of forensic science, especially crime scene investigation and DNA... Trace evidence is evidence that is found at a crime scene in small but measurable amounts. ... Toxicology (from the Greek words toxicos and logos [1]) is the study of the adverse effects of chemicals on living organisms [2]. It is the study of symptoms, mechanisms, treatments and detection of poisoning, especially the poisoning of people. ... This article does not cite any references or sources. ... Pharmacology (in Greek: pharmakon (φάρμακον) meaning drug, and lego (λέγω) to tell (about)) is the study of how drugs interact with living organisms to produce a change in function. ... Clinical chemistry (also known as clinical biochemistry, chemical pathology or pure blood chemistry) is the area of pathology that is generally concerned with analysis of bodily fluids. ...

A forensic toxicologist must consider the context of an investigation, in particular any physical symptoms recorded, and any evidence collected at a crime scene that may narrow the search, such as pill bottles, powders, trace residue, and any available chemicals. Provided with this information and samples with which to work, the forensic toxicologist must determine which toxic substances are present, in what concentrations, and the probable effect of those chemicals on the person.

Determining the substance ingested is often complicated by the body's natural processes (see ADME), as it is rare for a chemical to remain in its original form once in the body. For example: heroin is almost immediately metabolised into another substance and further to morphine, making detailed investigation into factors such as injection marks and chemical purity necessary to confirm diagnosis. The substance may also have been diluted by its dispersal through the body; while a pill or other regulated dose of a drug may have grams or milligrams of the active constituent, an individual sample under investigation may only contain micrograms or nanograms. ADME is an acronym in pharmacokinetics and pharmacology for Absorption, Distribution, Metabolism, and Excretion, and describes the disposition of a pharmaceutical compound within an animal or human body. ... For other uses, see Heroin (disambiguation). ... Structure of the coenzyme adenosine triphosphate, a central intermediate in energy metabolism. ... This article is about the drug. ... For other meanings of gram, see gram (disambiguation). ... The milligram (symbol mg) is an SI unit of mass. ... In the metric system, a microgram is 1/1,000,000 of a gram, or 1/1000 of a milligram, is one of the smallest units of weight/mass commonly used. ... The nanogram is an SI unit of mass (symbol ng) defined as: 1 ng = 1 × 10-12 kilogram (1 × 10-9 gram) A nanogram is one billionth (1/1,000,000,000) of a gram. ...

Samples

Urine

A urine sample is quick and easy for a live subject, and is common among drug testing for employees and athletes. Urine samples do not necessarily reflect the toxic substance(s) the subject was influenced by at the time of the sample collection. An example of this is THC from cannabinoid (for example, marijuana) use, which in heavy users can be detected in urine for up to 14 days following use. Note also that it can take as long as 8 hours until a given substance can be detected. Specific to workplace drug testing, urine collection MUST be directly observed due to the prevalence of substance abusers "beating the test" via sample substitution or adulteration. This article or section is in need of attention from an expert on the subject. ... Drug testing is a subject of a lot of controversy. ... Athletics, also known as track and field or track and field athletics, is a collection of sport events. ... “THC” redirects here. ... Cannabinoids are a group of chemicals which activate the bodys cannabinoid receptors. ... Cannabis, also known as marijuana[1] or ganja,[2] is a psychoactive product of the plant Cannabis sativa L. subsp. ...

Blood

A blood sample of approximately 10 cm³ is usually sufficient to screen and confirm most common toxic substances. A blood sample provides the toxicologist with a profile of the substance that the subject was influenced by at the time of collection; for this reason, it is the sample of choice for measuring blood alcohol content in drunk driving cases. Human blood smear: a - erythrocytes; b - neutrophil; c - eosinophil; d - lymphocyte. ... A cubic centimetre (cm3) is an SI derived unit of volume, equal to the volume of a cube with side length of 1 centi metre. ... Blood alcohol content (BAC) or blood alcohol concentration is the concentration of alcohol in blood. ... Drunk driving (drink driving in the UK) or drinking and driving is the act of operating a motor vehicle after having consumed alcohol (i. ...

Hair sample

Hair is capable of recording medium to long-term or high dosage substance abuse. Chemicals in the bloodstream may be transferred to the growing hair and stored in the follicle, providing a rough timeline of drug intake events. Head hair grows at rate of approximately 1 to 1.5 cm a month, and so cross sections from different sections of the follicle can give estimates as to when a substance was ingested. Testing for drugs in hair is not standard throughout the population. The darker and coarser the hair the more drug that will be found in the hair. If two people consumed the same amount of drugs, the person with the darker and coarser hair will have more drug in their hair than the lighter haired person when tested. This raises issues of possible racial bias in substance tests with hair samples. ^[1] For the 1968 stage production, see Hair (musical), for the 1979 film, see Hair (film). ... A hair follicle is part of the skin that grows hair by packing old cells together. ... For the novel by Michael Crichton, see Timeline (novel). ... A centimetre (American spelling centimeter, symbol cm) is a unit of length that is equal to one hundredth of a metre, the current SI base unit of length. ...

Oral fluid

Oral fluid is the proper term, however Saliva is used commonly. Saliva is a component of oral fluid. Oral fluid is composed of many components and concentrations of drugs typically parallel to those found in blood. Sometimes referred to as ultra filtrate of blood, it is thought that drugs pass into oral fluid predominantly through a process known as passive diffusion. Drugs and pharmaceuticals that are highly protein bound in blood will have a lower concentration in oral fluid. The use of oral fluid is gaining importance in forensic toxicology for showing recent drug use, e.g in clinical settings or investigation of driving under influence of substances.tt Saliva is the watery and usually frothy substance produced in the mouths of humans and some animals. ...

Other

Other bodily fluids and organs may provide samples, particularly samples collected during an autopsy. A common autopsy sample is the gastric contents of the deceased, which can be useful for detecting undigested pills or liquids that were ingested prior to death. In highly decomposed bodies, traditional samples may no longer be available. The vitreous humour from the eye may be used, as the fibrous layer of the eyeball and the eye socket of the skull protects the sample from trauma and adulteration. Other common organs used for toxicology are the brain, liver, spleen and stomach contents Post-mortem, postmortem and post mortem redirect here. ... In anatomy, the stomach (in ancient Greek στομάχι) is an organ in the alimentary canal used to digest food. ... Vitreous humour is the clear aqueous solution that fills the space between the lens and the retina of the vertebrate eyeball. ...

The inspection of the contents of the stomach must be part of every postmortem examination because it may provide qualitative information concerning the nature of the last meal and the presence of abnormal constituents. Using it as a guide to the time of death, however, is theoretically unsound and presents many practical difficulties, although it may have limited applicability in some exceptional instances. Generally, using stomach contents as a guide to time of death involves an unacceptable degree of imprecision and is thus liable to mislead the investigator and the court. Characteristic cell types from food plants can be used to identify a victim's last meal; knowledge about which can be useful in determining the victim's whereabouts or actions prior to death (Bock and Norris, 1997). Some of these cell types include (Dickison, 2000):

• sclereids (pears)
• starch grains (potatoes and other tubers)
• raphide crystals (pineapple)
• druse crystals (citrus, beets, spinach)
• silica bodies (cereal grasses and bamboos)

In a case where a young woman had been stabbed to death, witnesses reported that she had eaten her last meal at a particular fast food restaurant. However, her stomach contents did not match the limited menu of the restaurant, leading investigators to conclude that she had eaten at some point after being seen in the restaurant. The investigation led to the apprehension of a man whom the victim knew, and with whom she had shared her actual final meal (Dickison, 2000). Time since death can be approximated by the state of digestion of the stomach contents. It normally takes at least a couple of hours for food to pass from the stomach to the small intestine; a meal still largely in the stomach implies death shortly after eating, while an empty or nearly-empty stomach suggests a longer time period between eating and death (Batten, 1995). However, there are numerous mitigating factors to take into account: the extent to which the food had been chewed, the amount of fat and protein present, physical activity undertaken by the victim prior to death, mood of the victim, physiological variation from person to person. All these factors affect the rate at which food passes through the digestive tract. Pathologists are generally hesitant to base a precise time of death on the evidence of stomach contents alone.

Other organisms

Bacteria, maggots and other organisms that may have ingested some of the subject matter may have also ingested any toxic substance within it. Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ... This article is about the insect. ...

Detection and Classification

Detection of drugs and pharmaceuticals as in biological samples are usually done by an initial screening and then a further confirmation of right compound and quantification of that compound. The screening and confirmation is usually done with different analytical methods. Every analytical method used in forensic toxicology should be carefully tested with preforming a validation of the method to ensure correct and indisputable results at all time. A testing laboratory involved in forensic toxicology should adhere to some quality programme to ensure the best possible results and safety of any individual.

The choice of method for testing is highly dependent on what kind of substance one can suspect to find and what the material is that the testing is performed on. Biological samples have are more complex as factors as matrix effect, metabolism and conjugation of compounds has to be considered. Substances as such (powders, pills and liquids) have a much higher concentration and toxicology is aimed at finding what compounds constitutes the sample and at what concentrations.

Gas chromatography

Gas-liquid chromatography is of particular use in examining volatile organic compounds. Gas-liquid chromatography (GLC), or simply gas chromatography (GC), is a type of chromatography in which the mobile phase is a carrier gas, usually an inert gas such as helium or an unreactive gas such as nitrogen, and the stationary phase is a microscopic layer of liquid or polymer on... Benzene is the simplest of the arenes, a family of organic compounds An organic compound is any member of a large class of chemical compounds whose molecules contain carbon. ...

Detection of Metals

The compounds suspected of containing a metal is traditionally separated by the destruction of the organic matrix by chemical or thermal oxidation. This leaves the metal to be identified and quantified in the inorganic residue, and it can be detected using such methods as the Reinsch test, emission spectroscopy or X-ray diffraction. Unfortunately, while this identifies the metals present it removes the original compound, and so hinders efforts to determine what may have been ingested. The toxic effects of various metallic compounds can vary considerably. This article is about metallic materials. ... The Reinsch Test is an initial indicator to detect the presence of one or more of the following Heavy Metals in a biological sample, and is often used by toxicologists where poisoning by such metals is suspected. ... Extremely high resolution spectrogram of the Sun showing thousands of elemental absorption lines (fraunhofer lines) Spectroscopy is the study of the interaction between radiation (electromagnetic radiation, or light, as well as particle radiation) and matter. ... X-ray crystallography is a technique in crystallography in which the pattern produced by the diffraction of x-rays through the closely spaced lattice of atoms in a crystal is recorded and then analyzed to reveal the nature of that lattice. ... // Toxic and Intoxicated redirect here – toxic has other uses, which can be found at Toxicity (disambiguation); for the state of being intoxicated by alcohol see Drunkenness. ...

Nonvolatile organic substances

Drugs, both prescribed and illegal, pesticides, natural products, pollutants and industrial compounds are some of the most common compounds encountered. Screening methods include thin-layer chromatography, gas-liquid chromatography and immunoassay. For complete legal identification, a second confirmatory test is usually also required. The trend today is to use liquid chromatography tandem mass spectrometry, predeced with sample workup as liqiud-liquid extraction or solid phase extraction. Older methods include: spot test (see Pill testing), typically the Marquis Reagent, Mecke Reagent, and Froehde's Reagent for opiates, Marquis Reagent and Simon's reagent for amphetamine, methamphetamine and other analogs, like MDMA, the Scott's test for cocaine, and the modified Duquenois reagent for marijuana and other cannabinoids. For compounds that don't have a common spot test, like benzodiazepines, another test may be used, typically mass spectroscopy, or spectrophotometry. A cropduster spreading pesticide. ... Many of the compounds which are dangerous to the environment can also be harmful to humans in the long-term range and come from mineral and fossil sources or are produced by humans themselves. ... Gas-liquid chromatography (GLC), or simply gas chromatography (GC), is a type of chromatography in which the mobile phase is a carrier gas, usually an inert gas such as helium or an unreactive gas such as nitrogen, and the stationary phase is a microscopic layer of liquid or polymer on... In chemistry, a chemical test is qualitative or semi-quantitative procedure designed to prove the existence of a chemical compound or chemical group with the aid of a specific reagent. ... Pill Testing is a process used to identify substances contained within a pill, usually illicit substances. ... The Marquis reagent is used as a simple spot-test to presumptively identify alkaloids as well as other compounds. ... An opioid is any agent that binds to opioid receptors found principally in the central nervous system and gastrointestinal tract. ... The Marquis reagent is used as a simple spot-test to presumptively identify alkaloids as well as other compounds. ... Amphetamine or Amfetamine(Alpha-Methyl-PHenEThylAMINE), also known as beta-phenyl-isopropylamine and benzedrine, is a prescription stimulant commonly used to treat Attention-deficit hyperactivity disorder (ADHD) in adults and children. ... This article is about the psychostimulant, d-methamphetamine. ... ecstasy and religious ecstasy MDMA, most commonly known today by the street name ecstasy, is a synthetic entactogen of the phenethylamine family whose primary effect is to stimulate the brain to rapidly secrete large amounts of serotonin, causing a general sense of openness, empathy, energy, euphoria, and well-being. ... The Duquenois reagent is used in the Rapid Modified Duquenois-Levine test, a proven screening test for the presence of marijuana. ... Cannabis, also known as marijuana[1] or ganja,[2] is a psychoactive product of the plant Cannabis sativa L. subsp. ... Cannabinoids are a group of terpenophenolic compounds present in Cannabis (Cannabis sativa L). ... Benzodiazepine tablets The benzodiazepines are a class of drugs with hypnotic, anxiolytic, anticonvulsant, amnestic and muscle relaxant properties. ... Mass spectrometry is a technique for separating ions by their mass-to-charge (m/z) ratios. ... Spectrophotometer In physics, spectrophotometry is the quantitative study of electromagnetic spectra. ...

References

External links

• http://www.all-about-forensic-science.com/forensic-toxicology.html

See also

• Drug test