Drug testing methodologies

He is some information from Wikipedia about drug testing methodologies.

The different types of drug tests are tested in very similar ways. Before testing the sample, the tamper-evident seal is checked for integrity. If it appears to have been tampered with or was damaged in transit, the laboratory rejects the sample and does not test it.

One of the first steps for all drug tests is to make the sample testable. Urine and oral fluid can be used "as is" for some tests, but other tests require the drugs to be extracted from urine beforehand. Strands of hair, patches, and blood must be prepared before testing. Hair is washed in order to eliminate second-hand sources of drugs on the surface of the hair, then the keratin is broken down using enzymes. Blood plasma may need to be separated by centrifuge from blood cells prior to testing. Sweat patches are opened up and the sweat collection component is soaked in a solvent to dissolve any drugs present.

Laboratory-based drug testing is done in a two-tiered fashion using two different types of detection methods. The first is known as the screening test, and this is applied to all samples that go through the laboratory. The second, known as the confirmation test, is only applied to samples that test positive during the screening test. Screening tests are usually done by immunoassay (EMIT, ELISA, and RIA are the most common). A "dipstick" drug testing method which could at some future time provide screening test capabilities to field investigators has been developed at the University of Illinois.^[3] Screening tests are typically less sensitive and more prone to false positives and false negatives than the confirmation test.

After a suspected positive sample is detected during screening, the sample is flagged and tested using the confirmation test. Samples that are negative on the screening test are discarded and reported as negative. The confirmation test in most laboratories (and all SAMHSA certified labs) is performed using mass spectrometry, and is extremely precise but also fairly expensive to run. False positive samples from the screening test will be negative on the confirmation test. Samples testing positive during both screening and confirmation tests are reported as positive to the entity that ordered the test. Most laboratories save positive samples for some period of months or years in the event of a disputed result or lawsuit. For workplace drug testing, a positive result is generally not confirmed without a review by a Medical Review Officer that will normally interview the subject of the drug test.

Visit American Toxicology to see which methodologies we use.

Saliva drug screen / Oral fluid-based drug screen

Saliva / oral fluid-based drug tests can generally detect use during the previous few days. Saliva or oral fluid based drug tests are becoming more prevalent because of their convenience and the fact that they can not be adulterated. Furthermore, on-site oral based tests in particular enable the implementation of random testing programs, proven to be the most effective type of drug screening. Oral fluid based tests are as accurate as urine and can be obtained from suppliers in the United States. Testing is usually performed by employers, for either pre-employment, random, post-accident, reasonable suspicion, or return-to-duty testing. Oral fluid based testing most closely mimics results found with blood and is preferable for detecting on-the-job drug use or in post-accident applications in this case because the degree of intoxication can be approximated based on the amount of substance.

Detection in saliva tests begins immediately upon use:

• Marijuana and hashish (THC): An hour after ingestion, and up to 24 hours depending on use.
• Cocaine (including crack): From time of ingestion up to 2 to 3 days.
• Opiates: From time of ingestion up to 2 to 3 days
• Methamphetamine and ecstasy (MDMA, "crank," "ice"): From time of ingestion up to 2 to 3 days.
• Benzodiazepines: From time of ingestion up to 2 to 3 days

This helpful information was provided by Wikipedia.

For all saliva testing American Toxicology is partnered with Isaac Farrel who runs Lab Express another business in Las Vegas who handles a large portion of the cities swab testing.

Hair alcohol testing

As the hair grows, it absorbs special markers called fatty acid ethyl esters (FAEEs) and ethyl glucuronide (EtG) into its structure, which remain in the hair indefinitely. These markers are only produced when there is alcohol in the bloodstream, such that the more markers there are, the more alcohol you have consumed.

Tests detecting both FAEE and EtG levels have been used by UK courts.

Trimega Laboratories were the first company to commercialise FAEE testing in UK courts.^{[citation needed]} Tricho-Tech were the first company to commercialise EtG testing in UK courts.^{[citation needed]}

Analysis of hair samples has many advantages as a preliminary screening method for the presence of toxic substances deleterious to health after exposures in air, dust, sediment, soil and water, food and toxics in the environment. The advantages of hair analysis include the non-invasiveness, low cost and the ability to measure a large number of, potentially interacting, toxic and biologically essential elements. Hence, head hair analysis is now increasingly being used as a preliminary test to see whether individuals have absorbed poisons linked to behavioral health problems.[2]

The use of hair alcohol analysis to establish and verify persistent alcohol abusers within the United Kingdom has steadily increased in recent years.

In contrast to other drugs consumed, alcohol is not deposited directly in the hair. For this reason the investigation procedure looks for direct products of ethanol metabolism. The main part of alcohol is oxidized in the human body. This means it is released as water and carbon dioxide. One part of the alcohol reacts with fatty acids to produce esters. The sum of the concentrations of four of these fatty acid ethyl esters (FAEEs: ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate) are used as indicators of the alcohol consumption. The amounts found in hair are measured in nanograms (one nanogram equals only one billionth of a gram), however with the benefit of modern technology, it is possible to detect such small amounts.

However there is one major difference between most drugs and alcohol metabolites (FAEE) in the way in which they enter into the hair: on the one hand like other drugs FAEEs enter into the hair via the keratinocytes, the cells responsible for hair growth. These cells form the hair in the root and then grow through the skin surface taking any substances with them. On the other hand the sebaceous glands produce FAEEs in the scalp and these migrate together with the sebum along the hair shaft (Auwärter et al., 2001, Pragst et al., 2004). So these glands lubricate not only the part of the hair that is just growing at 0.3 millimeters per day on the skin surface, but also the more mature hair growth, providing it with a protective layer of fat.

FAEEs (nanogram = one billionth of a gram) appear in hair in almost one order of magnitude higher than (the relevant order of magnitude of) Etg (picogram = one trillionth of a gram). It has been technically possible to measure FAEEs since 1993, whereas the technique for measuring (the relevant range of) Etg is still in its infancy.

In practice, most hair which is sent for analysis has been cosmetically treated in some way (bleached, permed etc.). It has been proven that FAEEs are (surprisingly) not significantly affected by such treatments (Hartwig et al., 2003a). So far no systematic investigations in this regard have been carried out for Etg

FAEE concentrations in hair from other body sites can be interpretated in a similar fashion as scalp hair (Hartwig et al., 2003b). Etg: no information available.

Extensive studies involving over 1000 donors have been carried out since 2000. These have enabled us to establish reliable reference ranges for FAEEs with respect to drinking habits of the various groups: non-drinkers <> 1ng/mg

There are no reliable reference ranges for Etg from comprehensive studies. Further investigations are in progress to examine the applicability of the method in practice of the detection of alcohol abuse.

Literature Pragst F., Balikova M.A.: State of the art in hair analysis for detection of drugs and alcohol abuse; Clinica Chimic Acta 370 2006 17-49.

Auwärter V.: Fettsäureethylester als Marker exzessiven Alkoholkonsums – Analytische Bestimmung im Haar und in Hautoberflächenlipiden mittels Headspace-Festphasenmikroextraktion und Gaschromatographie-Massenspektrometrie. Dissertation Humboldt-Universität Berlin 2006.

Pragst F., Auwärter V., Kiessling B., Dyes C.: Wipe-test and patch-test ror alcohol misuse based on the concentration ratio of fatty acid ethyl esters and squalen CFAEE/CSQ in skin surface lipids. Forensic Sci Int 2004; 143:77-86.

This helpful information was provided by Wikipedia.

Which method of drug testing is the best?

Detection periods

The following chart from LabCorp gives approximate detection periods for each substance by test type.^[1] The ranges depend on amount and frequency of use, metabolic rate, body mass, age, overall health, and urine pH. For ease of use, the detection times of metabolites have been incorporated into each parent drug. For example, heroin and cocaine can only be detected for a few hours after use, but their metabolites can be detected for several days in urine. In this type of situation, we will report the (longer) detection times of the metabolites.

• NOTE 1: Oral fluid or saliva testing results for the most part mimic that of blood. The only exception is THC. Oral fluid will likely detect THC from ingestion up to a maximum period of 18-24 hours
• NOTE 2: Urine can not detect current drug use. It takes approximately 6–8 hours or more post-consumption for drug to be metabolized and excreted in urine. Similarly, hair requires two weeks, and sweat, seven days.

Approximate values for detection periods

Substance	Urine	Hair	Blood
Alcohol	3–5 days via ethyl gluconoride (EtG) metabolite or 10–12 hours via traditional method	lifetime of hair	12 hours
Amphetamines (except meth)	1 to 2 days	up to 90 days	12 hours
Methamphetamine	2 to 4 days	up to 90 days	24 hours
Barbiturates (except phenobarbital)	2 to 3 days	up to 90 days	1 to 2 days
Phenobarbital	7 to 14 days	up to 90 days	4 to 7 days
Benzodiazepines	Therapeutic use: 3 days. Chronic use (over one year): 4 to 6 weeks	up to 90 days	6 to 48 hours
Cannabis	Light use: 2-7 days Prolonged use: 1-3 months	up to 90 days	12 days
Cocaine	3 to 300 days with exceptions for certain kidney disorders	up to 90 days	24 hours
Codeine	1 day	up to 30 days	12 hours
Cotinine (a break-down product of nicotine)	2 to 4 days	up to 90 days	2 to 4 days
Morphine	2 days	up to 90 days	6 hours
Heroin	2 days (single use) 2-5 (chronic)	up to 90 days	6 hours
LSD	2 to 24 hours	up to 3 days	0 to 3 hours
Methadone	3 days	up to 30 days	24 hours
PCP	14 days; up to 30 days in chronic users	up to 90 days	24 hours

This helpful information was provided by wikipedia.

Obviously the drugs remain longer in the hair follicle than they do any where else. American Toxicology recommends that both hair and urine drug testing be used for optimal results.

Sweat drug screen

Although the sweat test is pretty cool, American Toxicology does not provide them. Here is some helpful information about the sweat drug test from wikipedia.

Sweat tests are patches attached to the skin to collect sweat over a long period of time (10–14 days). These are almost exclusively used by child protective services, parole departments, and other government institutions concerned with drug use over long periods, when urine testing is not practical. The patches have security features that keep them from being covertly removed and then reapplied without the knowledge of the testing agency. At the end of the test period, the patch is removed by a social worker or parole officer and sent to a lab for analysis. If the person has used any drugs during the period that the patch was in place, they will test positive for that drug. This type of testing has fallen out of favor with government agencies due to documented problems with certain drugs^[2].
This information was provided by wikipedia.

Sampling for Hair Follicle Drug Testing

How to effectivly collect a hair sample for drug testing according to American Toxicology Laboratory in Las Vegas, Nevada.






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The patient in this exmple is a worker in our laboratory.