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- Natural/synthetic substance: produces physiological/ psychological effects. Narcotics: (analgesics) relieve pain by depressing the central nervous system. The most common source for these narcotic drugs is opium, extracted from poppies.
- Morphine: extracted from opium/synthesize heroin. Heroin: drowsiness/sense of well-being/three to four hours.
- OxyContin: (oxycodone) same physiological effects on the body as opium narcotics. -chronic pain. Methadone: synthetic opiate -given to heroin addicts -given for pain
- varies in different parts of the plant, generally decreasing in the following sequence: resin, flowers, leaves, with little THC in the stem, roots or seeds. Marijuana does not cause physical dependency, but the risk of harm is in heavy, long-term use.
- Other hallucinogens include LSD, mescaline, PCP, psilocybin, and MDMA (Ecstasy). LSD is synthesized from lysergic acid, and can cause hallucinations that can last for 12 hours. Phencyclidine, or PCP, is often synthesized in clandestine laboratories and is often smoked, ingested, sniffed. Phencyclidine is often mixed with other drugs, such as LSD, or amphetamine, and is sold as a powder (“angel dust”), capsule, or tablet. Oral intake of PCP first leads to feelings of strength and invulnerability, which may turn to depression, tendencies toward violence, and suicide.
- Depressants are another class of drugs. Depressants are substances used to depress the functions of the central nervous system. Depressants calm irritability and anxiety and may induce sleep. These include alcohol (ethanol), barbiturates, tranquilizers, and various substances that can be sniffed, such as airplane glue, model cement, or aerosol gas propellants such as freon.
- Alcohol (ethyl alcohol) enters the body’s bloodstream and quickly travels to the brain, where it acts to suppress the brain’s control of thought processes and muscle coordination. Barbiturates, or “downers,” are normally taken orally and create a feeling of well-being, relax the body, and produce sleep. Tranquilizers, unlike barbiturates, produce a relaxing tranquility without impairment of high-thinking faculties or inducing sleep. Sniffing has immediate effects such as exhilaration, but impairs judgment and may cause liver, heart, and brain damage, or even death.
- which in its free-base form is known as crack . Stimulants are substances taken to increase alertness or activity, followed by a decrease in fatigue and a loss of appetite.
- Meth: -snorted/injected/smoked/orally -newest drug scourge -highly addictive Cocaine: coca leaves -alertness/vigor -suppression of hunger/fatigue/boredom. -Crack is cocaine mixed with baking soda and water, then heated. -Crack is often smoked in glass pipes, and like cocaine stimulates the brain’s pleasure center. -1980’s-epeidemic in U.S.
- Synthetic drugs: -nightclubs/bars/raves -MDMA (Ecstasy) -GHB (gamma hydroxybutyrate) -Rohypnol (“Roofies”) -Ketamine (Special K) -GHB/Rohypnol: -CNS depressants -date rape/robbery drugs
- Ecstacy: (X) Methylenedioxymethamphetamine -synthetic/mind-altering -enhances self-awareness -decreases inhibitions -seizures/stroke/kidney failure/cardiac arrest Ketamine: -animal anesthetic -impaired motor functions/high blood pressure/amnesia/mild respiratory depression.
- Synthetic: -abused by individuals who are interested in accelerating muscle growth. -unpredictable effects on mood and personality/ depression/diminished sex drive/halting bone growth/liver cancer.
- Controlled Substances Act: -Five schedules of classification - potential for abuse/physical and psychological dependence/medical value
- such as cocaine, PCP, and most amphetamine and barbiturate prescriptions. Schedule III drugs have less potential for abuse and a currently accepted medical use such as all barbiturate prescriptions not covered under Schedule II, such as codeine and anabolic steroids
- such as darvon, phenobarbital, and some tranquilizers such as diazepam (valium) and chlordiazepoxide (librium). Schedule V drugs must show low abuse potential and have medical use such as opiate drug mixtures that contain nonnarcotic medicinal ingredients.
- The field investigator has the responsibility of ensuring that the evidence is properly packaged and labeled for the laboratory. Generally common sense is the best guide, keeping in mind that the package must prevent the loss of the contents and/or cross-contamination. Often the original container in which the drug was seized will suffice. All packages must be marked with information that is sufficient to ensure identification by the officer in the future and establish the chain of custody. To aid the drug analyst, the investigator should supply any background information that may relate to a drug’s identity.
- The challenge or difficulty of forensic drug identification comes in selecting analytical procedures that will ensure a specific identification of a drug. This plan, or scheme of analysis, is divided into two phases. Screening test that is nonspecific and preliminary in nature to reduce the possibilities to a manageable number. Confirmation test that is a single test that specifically identifies a substance.
- Faced with the prospect that the unknown substance may be any one of a thousand or more commonly encountered drugs, the analyst must employ screening tests to reduce these possibilities to a small and manageable number. This objective is often accomplished by subjecting the material to a series of color tests that will produce characteristic colors for the more commonly encountered illicit drugs. Microcrystalline tests can also be used to identify specific drug substances by studying the size and shape of crystals formed when the drug is mixed with specific reagents.
- Once this preliminary analysis is completed, a confirmational determination is pursued. Forensic chemists will employ a specific test to identify a drug substance to the exclusion of all other known chemical substances. Typically infrared spectrophotometry or gas chromatography-mass spectrometry is used to specifically identify a drug substance.
- Another consideration in selecting an analytical technique is the need for either a qualitative or a quantitative determination. The former relates just to the identity of the material, whereas the latter requires the determination of the percent composition of the components of a mixture.
- Chromatography is a means of separating and tentatively identifying the components of a mixture. The theory of chromatography is based on the observation that chemical substances have a tendency to partially escape into the surrounding environment when dissolved in a liquid or when absorbed on a solid surface. Those materials that have a preference for the moving phase will slowly pull ahead and separate from those substances that prefer to remain in the stationary phase.
- Thin Layer Chromotography (TLC) uses a solid stationary phase usually coated onto a glass plate and a mobile liquid phase to separate the components of the mixture. The liquid will slowly rise up the plate by capillary action causing the sample to become distributed between the stationary phase and the moving liquid phase. Because most compounds are colorless, the materials must be visualized by placing the plates under ultraviolet light or spraying the plate with a chemical reagent. The distance a spot travels up a thin-layer plate can be assigned a numerical value known as the R f value.
- In GC, the moving phase is actually a gas called the carrier gas, which flows through a column. The stationary phase is a thin film of liquid contained within the column. After a mixture has traversed the length of the column, it will emerge separated into its components. The written record of this separation is called a chromatogram. The time required for a component to emerge from a GC column is known as retention time
- Light is described as a continuous wave. When white light passes though a prism, it is dispersed into a continuous spectrum of colors. Waves are described in terms such as: Wavelength, the distance between two successive crests (or one trough to the next trough). Frequency, the number of crests (or troughs) passing any one given point per unit of time. The electromagnetic spectrum is the entire range of radiation energy from the most energetic cosmic rays to the least energetic radio waves. Visible light is only a small part of the electromagnetic spectrum.
- Just as a substance can absorb visible light to produce color, many of the invisible radiations of the electromagnetic spectrum are likewise absorbed. Spectrophotometry, an important analytical tool, measures the quantity of radiation that a particular material absorbs as a function of wavelength and frequency.
- The spectrophotometer is the instrument used to measure and record the absorption spectrum of a chemical substance. The components of a spectrophotometer are: A radiation source A monochromator or frequency selector A sample holder A detector to convert electromagnetic radiation into an electrical signal A recorder to produce a record of the signal Absorption spectra can be done in the visible, ultraviolet (UV) or infrared (IR) regions.
- Currently, most forensic laboratories use UV and IR spectrophotometers to characterize chemical compounds. The simplicity of the UV spectrum facilitates its use as a tool for determining a material’s probable identity, although it may not provide a definitive result. The IR spectrum provides a far more complex pattern. Different materials always have distinctively different infrared spectra; each IR spectrum is therefore equivalent to a “fingerprint” of that substance.
- In the mass spectrometer, a beam of high-energy electrons collide with a material, producing positively charged ions. These positive ions almost instantaneously decompose into numerous fragments, which are separated according to their masses. The unique feature of mass spectrometry is that under carefully controlled conditions, no two substances produce the same fragmentation pattern.
- A direct connection between the GC column and the mass spectrometer allows each component to flow into the mass spectrometer as it emerges from the GC. The separation of a mixture’s components is first accomplished by the GC. Then, fragmentation of each component by high-energy electrons in the mass spectrometer, will produce a distinct pattern, somewhat like a “fingerprint”, of the substance being examined.