Forensic Identification of Marijuana: Final Study Guide
Column Chromatography theory
Takes advantage of analyte and phase affinities for separation. It is based on the strength of molecular forces. It can also cause separation based on size. This is common in gas chromatography. Solvent (liquid or gas) carries analyte through column coated with stationary phase.
Pistillate
female. part of the flower. It has pistols. The female plant has tendrils on top. - Female plants have flowers that are more densely packed, shorter, and have pistols on the tops of their flowers.
Chromatography theory
Takes advantage of the different affinities of the analyte(s) for the mobile and stationary phases to achieve separation of complex mixtures of organic molecules. - Analyte/mobile phase - Analyte/stationary phase - Mobile phase/stationary phase
Cannabis ruderalis
species that grows primarily in Russia. Short and skinny.
Marinol (dronabinol)
synthetic delta-9- tetrahydrocannabinol (delta-9-THC) Controlled Substance Schedule III Weight loss associated with AIDS, antiemetic for cancer patients undergoing chemotherapy
Cannabis sativa L.
The most commonly recognized species of marijuana. A very tall and skinny plant.
Ultra Performance Liquid Chromatography (UPLC)
Under extreme pressure
Mobile phase of TLC
Usually nonpolar organic solvents. - can be a pure organic solvent or a mixture - If you consider the overall polarity, still needs to be mostly nonpolar
hemp
Variety of the cannabis plant. Grown and utilized for its fiber. - THC content of less than 0.5 weight % - Highly regulated. Kansas statute states THC content must be less than 0.3 weight % to be considered this.
Leaflet
Will be *lanceolate* (will have serrated edges). Also are *pinnately veined* (opposite veins on the left and right line up and share a common point.
isocratic elution
composition of the mobile phase remains constant throughout the entire separation in LC
Hydrogen Bonding
H bonded to O, N, or F (highly electronegative); partial positive/negative
positive - yes it is marijuana negative - no it is not marijuana Inconclusive
How could you answer professionally if asked "is this marijuana"?
- first individually. This stopped working when new structures emerged. - next, we scheduled them by structural classes. Blanket control of SynCans as schedule I substances.
How did we try to control SynCans?
All parts of the plant and all varieties of cannabis except for the mature stalk (which doesn't contain THC naturally)
How does the state (Kansas) define "Marijuana"?
Molecular Ion (M+)
the peak of highest mass in a mass spectrum; it has the same mass as the molecule from which it came. Usually located farthest left.
Base peak
the tallest peak in a mass spectrum. Represents the most stable fragment detected.
Cannabis indica
plant species of marijuana. Shorter and bushier species.
Normal Phase HPLC
polar stationary phase, non-polar mobile phase
Modified Duquenois-Levine
- First comes solvent extraction. (petroleum ether is used). -Add Duquinois reagent. Made up of vanilla, acetaldehyde, absolute ethanol. - Add concentrated HCl acid. - Chloroform extraction creates 2 layers (chloroform layer on the bottom) Test is done in a test tube or spot plate
Duquenois-Negm
- First, soak the plant material in a non-polar solvent extract (the solvent is then removed and evaporated). - next, add duquenois reagent to the remaining extract. - Last, add some drops of hydrochloric acid.
Stationary phase of TLC
- Thin layer is deposited on a plate (silica gel, SiO2) - Can be deposited with or without a fluorescent indicator. A visualizing reagent instead.
High Performance Liquid Chromatography (HPLC)
- similar to gas chromatography, but uses liquid under pressure instead of gas - The whole process is under computer control, hence higher performance - HPLC uses high pressure and columns uses gravity.
Reasons for a drugs initial placement as a controlled substance
1. The drugs actual or relative potential for abuse. 2. Scientific evidence of the drug's. pharmacological effects, if known. 3. The state of current scientific knowledge regarding the substance. 4. Its history and current pattern of abuse. 5. The scope, duration, and significant of abuse. 6. What, if any, risk there is to the public health 7. The drug's psychic or physiological dependence liability. 8. Whether the substance is an immediate precursor of a substance already controlled.
Leaf
3-11 leaflets for marijuana. Typically 5-7; *there will always be an odd number of leaflets*, they will cluster around a central axis point. Palmate shape (like a fan).
Alaska, California, Colorado, Illinois, Maine, Massachusetts, Michigan, Nevada, Oregon, Vermont, Washington
33 states and Washington D.C. have legalized medical marijuana (some states have limitations). Which eleven states have legalized recreational marijuana usage?
Cannabidiol (CBD)
A cannabinoid found in the cannabis plant. - Doesn't give the "high" associated with THC. - legal in Kansas, but controlled federally. CBD oil is legal in some states where medical marijuana is not.
Column
A chromatography type that is also called "tubullar", and takes place in a small long tube. - Capillary electrophoresis - Gas chromatography - High pressure liquid chromatography - Ion chromatography
Planar
A chromatography type that takes place on a flat surface. - gel electrophoresis - pater chromatography - thin layer chromatography
Liquid chromatography (LC)
A type of chromatography for the separation of compounds that are soluble in a liquid phase; separates compounds by polarity (even though it can separate by size like GC)
Thin Layer Chromatography (TLC)
A type of chromatography that uses silica gel or alumina on a card as the medium for the stationary phase
Gas Chromatography (GC)
A type of chromatography used to separate vaporizable compounds; the stationary phase is a crushed metal or polymer and the mobile phase is a nonreactive gas.
Anti-Drug Abuse Act of 1986
Allowed for some drugs that were not specifically controlled to be treated as controlled substances as long as they were... - Structurally similar OR pharmacologically similar to a schedule I or II substance - AND intended for human consumption
Presumptive testing
Also called a "color test" or a "spot test". They can only indicate a class or type of compound. - They are NOT specific to a single substance/compound/drug. They may have false positives (eg. patchouli oil, coffee) - Informs for further testing, helps to select best procedure. - Always performed with positive and negative controls in the lab. Can be used to support probable cause in Law enforcement.
Intermolecular
Between separate molecules. Ex. Hydrogen bonding, Dipole-dipole, Dispersion forces
independent
Color is ______________ of mobile phase, but spot arrangement isn't.
TLC system
Composed of... - A development tank. A closed system ("saturated system") Has a filter paper soaked in solvent/mobile phase, saturating the air with the mobile phase. An open system ("unsaturated system") don't have filter paper soaked in mobile phase. - a visualizing reagent: based on analyte of interest. Allows for detection of separated compounds. Calculation of Rf.
- SynCans discovered by research groups and entered illicit market. - They began to be explicitly banned. - New drugs entered the market, and the cycle continued
Describe the evolution of Synthetic cannabinoids
Shouldn't
Drug chemists ______________ give an opinion regarding species.
add or remove a functional group
How are new drugs created to avoid legal repercussions?
Earlier elution
In LC, a lower retention time indicates ________________.
Polar, nonpolar
In TLC theory, __________ compounds travel more slowly than _____________ compounds because they interact with the polar silica. - Hydrogen bonding with -OH groups in silica. Often -OH or -NH2 groups in compounds will bond with silica (silica is usually the stationary phase).
nonpolar, nonpolar
In TLC theory, ___________ compounds travel more quickly with the typically ___________ solvents. - "like dissolves like", more soluble and less affected by polar silica.
Isothermal
In gas chromatography process, only one temperature is maintained during the entire prccess.
Staminate
Male flower. It has stamens. - male plants have flowers that are sparse and grouped very loosely. Male plants are generally taller than female plants.
Simple covering hair
Microscopic characteristic of Marijuana. Hair located on the *bottom side* of the leaflet. Long and skinny.
Cystolithic hairs
Microscopic characteristic of Marijuana. Hair located on the *top side* of the leaflet. Short and thick, look like bear/cat claw. Made of calcium carbonate.
Glandular hair
Microscopic characteristic of Marijuana. Hair that contains the resin bodies (which contain the most THC). Found in flowering plants.
Hash Oil
More concentrated form of Hash/Hashish
Dispersion forces
Non-polar molecules. Weakest
synthetic cannabinoids/"SynCans"
Part of a group called "NPS" (novel psychloactive substances). They are drugs that are dissolved in colatile liquid and then sprayed onto inactive plant material. They aren't natural. They are also sometimes called "designer drugs". Similar in activity to cannabinoids (so they have similar effects). - They were created to evade drug tests and/or scheduling.
80s and 90s
Original SynCans were discovered in the ______________. - Pfizer (CP series) - Sterling Group (WIN series) - Huffman (JWH series)
Dipole-Dipole Interactions
Polar molecules
Seeds
Produced by a female plant. They have an *Achene* pattern (looks almost like a tortoise shell), and are oval shaped.
Positive result
Purple color develops with addition of HCl. The purple color extracts into the chloroform layer. - Test tube: darker purple over lighter purple - Spot plate: "purple eye" Color may vary from indigo to nearly black-purple. (effected by concentration, pH, and compounds present).
temperature programming
Raising the temperature of a gas chromatography column during a separation to reduce the retention time of late-eluting components. - this cuts down analysis time - allows for separation of earlier compounds at lower column temperatures.
Resin, Flower, Leaflet, Stem, Seed/Root
Rank the parts of a Marijuana plant in order of decreasing TCH content (most to least).
Hash/Hashish
Resin extracted from female flowers. A more concentrated THC than Marijuana.
Retention values
Rf = a/b Also called "Retardation values". Useful for identification. It is a measurable value for a spot. - Constant value for a solvent/solvent system at a given concentration. - Measurable value for comparison of unknowns. Requires... - distance traveled by solvent front (a) - distance traveled by analyte (b). Measures to center of its spot. THIS VALUES IS ALWAYS LESS THAN 1.
Palmate shape
Shaped like a fan.
Covalent bond
Share electrons
S3187 Part D
Signed into effect in 2012 by the president. Defined "Cannabimimetic" analog. - one of the defined structural skeletal classes - accounted for isomers and substituents at specific positions - accounted for pharmacological aspect Extended emergency scheduling (2+1 years)
increases
THC content varies during the plants life cycle. Generally _______________ (peaks at full bloom). THC content is present at all stages. - Make and female plants have different THC contents.
TLC of marijuana
Solvents: - 100% Toluene (open system) - Hexane to diethyl ether (4:1) - Hexane to dioxane (4:1) Visualizer - *fast blue 2B*. 0.5% (weight per volume) aqueous solution. Developed with the aid of heat
reverse phase HPLC
Stationary phase is nonpolar, so more polar will move further
- they were sold illegally in the market - They were not scheduled, and we knew little about them. We didn't look for them. - Canines were not trained to find them
SynCans were designed to evade retribution. How did they do so?
2004
Synthetic cannabinoids started becoming popular in ________. They were called "spice", "herb incense", "K2". They were marketed as "legal" marijuana. They were marked "not for human consumption" in order to avoid it being considered a controlled substance.
Cesamet (nabilone)
THC analogue (differs slightly from THC) Controlled Substance Schedule II Antiemetic for cancer patients undergoing chemotherapy
Tetrahydrocannabinol (THC)
The primary active ingredient in marijuana. - Depending on nomenclature system, could be called delta 1 or delta 9 trans-________________. delta 9 is more common. - controlled under the CSA as a schedule 1 substance.
Stalk
This is *fluted* (has ridges on it like bumps) and the leaflets are near the top of the plant.
Ionic bonding
Transfer of electrons; electronegativity differences. Strongest bond.
Sinsemilla
Very potent form of Marijuana; produced by removing all of the make plants prior to the female plants being pollinated. Results in a higher THC content in the plant as female plants don't have to use energy for reproduction. They are CULTURED (not a natural occurance)
The current status for medical use and treatment - Schedule I: none recognized, no accepted medical use - Schedule II: accepted, may have severe limitations The available info regarding the safety of use - schedule I: lacks sufficient information The potential for abuse The drug's psychic or psychological dependence liability. - I/II: Severe psychic or physical - III: High psychic; moderate - low physical - IV: Limited psychic or physical vs. III - V: Limited psychic or physical vs. IV
What are some of the reasons behind a drugs placement in a certain schedule?
- connected to carrier gas line - sample is injected via inlet needed to vaporize sample - column is mounted in oven - Separated compounds are venter or transferred to detector - Data system "translates" collected info from detector
What are the parts of gas chromatography?
- Connect to one or more mobile phase reservoirs - A pump to mix and move mobile phase - Injector - Thermostated column for constant temperature - seperated compounds will go either to waste, are collected, or transferred to a detector (mass spec) - Data system "transplates" collected info from the detector
What are the parts of liquid chromatography (HPLC/UPLC)?
- An ionization source (can be electron ionization EI, or chemical ionization CI) - A Mass analyzer (quadrapoles and an ion trap) - Ion detector - the system should be under vacuum
What are the parts of mass spectrometry?
Pros: high sensitivity, thermally labile compounds, can be nondestructive, optimizable separation. Cons: very expensive, particulate free required
What are the pros and cons of using Liquid Chromatography?
Pros: cheaper, faster, and easier to use Cons: Must be volatile, destructive (the sample is lost)
What are the pros and cons of using gas chromatography?
Orange/red
What color is CBD (Cannabidiol) in the TLC of marijuana?
Purple
What color is CBN (cannabinol) in the TLC of marijuana?
Cherry red
What color is THC in the TLC of marijuana?
Cannabaceae
What is the family of Marijuana? - related families are Moraceae (mulberry), Ulnaceae (elm), and Urticaeceae (nettle)
Cannabis L.
What is the genus of Marijuana?
Rosales
What is the order of Marijuana?
- Can use MS (MS/MS is common now. Used for quants) - can be interfaced with variety (RI, UV, IR, Fluorescence)
What kinds of detectors can be used for LC?
Intramolecular
Within the same molecule. Ex. Ionic and covalent
Marijuana
a schedule I substance under the Controlled Substance Act (Federal act passed in the 60s). - Has a high potential for abuse - Currently not accepted for medical use in the US - Lack of accepted safety for use under medical supervision
Mass spectrometry theory (MS)
a technique that separates particles according to their mass. It fragments compounds to form ions. Compounds are bombarded with electrons to create positively charged ions. - ions are sorted by mass-to-charge ratio - used to detect ions that are formed and their relative abundance in the substance. - converts data to a mass spectrum. This makes the test reproducible and predictable for a specific compound.
gradient elution
chromatography in which the composition of the mobile phase is progressively changed to increase the eluent strength of the solvent. - this allows for more efficient separation of compounds - compounds that would be retained much longer using isocratic elution can be eluted faster.