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Chapter 12 Forensic Science
Forensic Science (CHEM1118)
Fairleigh Dickinson University
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Drugs
● Drug ○ Can be defined as a natural or synthetic substance that is used to produce physiological or psychological effects in humans or other higher order animals. ● Drug Defendence ○ In assessing the potential danger of drugs, society has become particularly conscious of their effects on human behavior. ○ Psychological Dependence ■ The conditioned use of a drug caused by underlying emotional needs. ○ Physical Dependence ■ Physiological need for a drug that has been brought about by its regular use. Dependence is characterized by withdrawal sickness when administration of the drug is abruptly stopped. ● Narcotic Drugs ○ Analgesic or pain-killing substance that depresses vital body functions such as blood pressure, pulse rate, and breathing rate. The regular administration of narcotics will produce physical dependence. ○ Analgesic ■ A drug or substance that lessens or eliminates pain. ● Hallucinogens ○ A substance that induces changes in mood, attitude, thought, or perception. ○ Marijuana ■ Marijuana refers to a preparation derived from the plant Cannabis. ■ Consists of crushed leaves mixed in varying proportions with the plants flower, stem, and seed. ● Depressants ○ Alcohol ■ Its major behavioral effects derive from its depressant action on the central nervous system. ○ Depressant ■ A substance used to depress the functions of the central nervous system. Depressants calm irritability and anxiety and may induce sleep. ● Stimulants ○ A substance taken to increase alertness or activity. ○ Amphetamine ■ A group of synthetic drugs that stimulate the central nervous system. ○ Cocaine ● Club Drugs ○ Synthetic drugs that are used at nightclubs, bars, and raves. ○ MDMA (ecstacy), GHB, Rohypnol, ketamine, and methamphetamine. ● Anabolic Steroids
○ Synthetic compounds that are chemically related to the male sex hormone testosterone. ● Controlled Substances Act ○ The federal law establishes 5 schedules of classification for controlled dangerous substances on the basis of a drug’s potential for abuse, potential for physical and psychological dependence, and medical value. ● Drug Identification ○ The presence of a huge array of powders, tablets, capsules, vegetable matter, liquids, pipes, cigarettes, cookers, and syringes is testimony to the vitality and sophistication of the illicit drug market. ● Screen Test ○ A test that is nonspecific and preliminary in nature. ● Confirmation ○ A single test that specifically identifies a substance. ● Color Tests ○ Many drugs yield characteristic colors when brought into contact with specific chemical reagents. ○ 5 preliminary color test reagents are: ■ Marquis ● The reagent turns purple in the presence of heroin and morphine and most opium derivatives. ■ Dillie-Koppanyi ● This is a valuable screening test for barbiturates, in whose presence the reagent turns violet-blue in color. ■ Duquenois-Levine ● A valuable color test for marijuana, performed by adding solutions A, B, and C, respectively, to the suspect vegetation. ■ Van Urk ● Reagent turns blue-purple in the presence of LSD. ■ Scott Test ● Color test for cocaine. A powder containing cocaine will turn solution a blue color, upon addition of B, the blue powder is transformed to a clear pink color. Upon addition of C, if cocaine is present, the blue color reappears in the chloroform layer. ● Microcrystalline Tests ○ Tests to identify specific substances by the color and morphology of the crystals formed when the substance is mixed with specific reagents. ● Spectrophotometry ○ The selective absorption of light by drugs in the UV and IR regions of the electromagnetic spectrum provides a valuable technique for characterizing drugs. ● Mass Spectrometry
Chapter 12 Forensic Science
Course: Forensic Science (CHEM1118)
University: Fairleigh Dickinson University
