Herb testing describes various drug test methodologies for cannabis use in medicine, sports, and law. The use of marijuana is very detectable and can be detected with urinalysis, hair analysis, and saliva tests for several days or weeks.
Unlike alcohol, the damage can be reasonably measured using a breathalyser (and confirmed by measurement of the alcohol content in the blood), valid detection of marijuana is time-consuming, and the test can not determine the approximate degree of damage. The lack of suitable tests and agreed levels of poisoning is a problem in the legality of marijuana debate, especially regarding drunk driving.
The concentrations obtained from such an analysis can often be helpful in distinguishing the active use of passive exposure, the elapsed time since use, and the level or duration of use.
The Duquenois-Levine test is commonly used as a screening test in the field, but it can not confirm the existence of marijuana definitively, as a large number of substances have been shown to give false-positive results.
Video Cannabis drug testing
Biology timeline
Most cannabinoids are lipophilic compounds (fat soluble) easily stored in fat, resulting in long elimination half-life relative to other recreational drugs. THC molecules, and related compounds, are usually detected in urine drug tests from 3 days to 10 days according to Redwood Laboratories; heavy users can produce positive tests for 1-3 months after stopping marijuana use. The length of time varies greatly according to the metabolism, quantity, and frequency of use.
Maps Cannabis drug testing
Test method
Urine test
The use of cannabis can be detected up to 3-5 days after exposure for rare users; for heavy users: 1-15 days; for chronic users and/or users with high body fat: 1-30 days
Under a typical 50Ã, ng/mL cutoff for THC in the United States, occasional or on-off users will be very likely to test positively over 3-4 days since last use, and chronic users will not be able to test many positive things. beyond 7 days. Using a more sensitive cutoff of 20 ng/mL (less common but still used by some labs), the maximum possible time is 7 days and 21 days, respectively. In exceptional circumstances of extended marijuana use, a detection time of more than 30 days is possible in some individuals at a 20 ng/mL cutoff.
However, each individual is different, and the timing of detection may vary due to metabolism or other factors. It also depends on whether the actual THC or THC metabolites are being tested, the latter having a longer detection time than the first. THC (found in cannabis) can only be detected in saliva/oral fluids for 2-24 hours in many cases.
The main metabolite excreted in urine is 11-or-delta9-tetrahydrocannabinol-9-carboxylic acid (delta9-THC-COOH). Most THC drug tests produce positive results when the concentration of marijuana in the urine exceeds 50 ng/mL. Urine testing is an immunoassay-based test on the principle of competitive binding. Drugs that may be present in urine specimens compete with each drug conjugate for binding sites in their specific antibodies. During the test, urine specimens migrate upward by capillary action. The drug, if present in a urine specimen under cut-off concentration, will not saturate its specific antibody binding site. The antibodies will then react with the drug-protein conjugate and the visible colored line will appear on the test line area of ​​the particular drug strip.
The use of marijuana is included in the "10-panel urine screen", as well as "SAMHSA-5", five drugs tested in a standard NIDA-approved drug test.
False positives have been known to be triggered by consuming flaxseed and other products, although more detailed and more expensive mass spectrometer-chromatography (GCMS) tests can tell the difference.
In 2011, researchers at John Jay College of Criminal Justice reported that dietary zinc supplements can mask the presence of THC and other drugs in the urine. Similar claims have been made on web forums on that topic. However, a 2013 study conducted by researchers at the University of Utah School of Medicine denied the possibility of using self-produced zinc with a false-negative urine drug test.
Known general pharmaceutical drugs that cause a positive error in the instant THC dye test include:
- Efavirenz,
- Ibuprofen,
- Ketoprofen,
- Naproxen,
- Piroxicam,
- Promethazine,
- Proton pump inhibitor,
- Sulindac,
- Tolmetin
Duquenois-Levine Reagent
The Duquenois-Levine test is a simple chemical color reaction test originally developed in 1930 by Pierre DuquÃÆ' Â © nois.
To carry out the test, a policeman should only open the seal on a small micropipette of chemicals, and insert the particles of suspected substances; if the chemicals turn purple, this indicates the possibility of marijuana. But the color variations can be subtle, and the readings may vary by testers.
It was adopted in 1950 by the United Nations as the preferred test for cannabis.
Azo dye (Fast Blue B/BB)
The United Nations Office for Drugs and Crime (UNODC) found azo dye Fast Blue B (3,3'-dimethoxybiphenyl-4,4'-bisdiazonium chloride) and Fast Blue BB CBD Beam Test
In 1911, Dr. W. Beam found that flax tissue, which is usually low in THC but high in the CBD, provides a purple color when treated with a base. The test is relatively simple and inexpensive, and usually involves placing the test sample in a 5% solution of potassium hydroxide and 95% ethanol. After about ten minutes, the sample with CBD showed a purple/purple/pink color. This test is specific to CBD and does not react to THC.
Hair test
The use of marijuana can be detected by hair tests and is generally included in standard hair tests. Hair tests generally take the latest 1.5-inch growth and use it for testing. It gives a detection period of about 90 days. If a person's hair is shorter than 1.5 inches, this detection period will be shorter. The detection window for cannabis body hair testing will be longer, as body hair grows slower than head hair and distorts the time period of detection. The hair drug test measures the parental metabolites of marijuana embedded in the hair shaft and removes external contamination as a source of positive results. The hair detection test window for cannabis can be as low as 1 pg/mg.
Saliva test
Marijuana was detected by saliva testing. Just like a blood test, saliva tests detect the presence of parental drugs and not inactive metabolites. This results in a shorter detection window for cannabis through saliva testing. Delta 9 THC is the parent compound. If the saliva sample is tested in the laboratory, the detection rate can be as low as 0.5 ng/mL (up to 72 hours after intake) and if an instant saliva drug test is in place, the cutoff rate is generally 50 ng./mL (up to 12 hours after intake). Per National Institute on Drug Abuse saliva drug testing provides a plausible alternative to other drug testing methods.
Blood tests
Marijuana is detected in the blood for about 12-24 hours, with severe/frequent use detected in the blood up to 7 days. Because they are invasive and difficult to administer, blood tests are rarely used. They are usually used in accident, injury and DUI investigations.
Urine contains THC-COOH, while hair, oral and sweat fluids contain THC. Blood can contain both substances, with relative amounts dependent on current and usage levels.
Neurological test
Although highly unlikely to be used, and more unlikely in court, Electroencephalography or EEG shows somewhat persistent alpha waves with slightly lower frequencies than usual. Cannabinoids produce "signs of depression of motor activity" through activation of neuronal cannabinoid receptors belonging to the CB1 subtype.
Legal use
Although there are blood, urine, and hair tests that can track the marijuana's active ingredients in the body, the marijuana lasts for a certain period of time for one of these tests to determine the actual intake time. Also, variations between different metabolisms make objective marijuana intoxication tests extremely difficult. Cannabis tests are common in drunk driving research, as well as in trial period guidelines.
References
Source of the article : Wikipedia
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