Studying Helps Little With Drug Tests 

Studying Helps Little With Drug Tests 
Posted by FoM on July 06, 2000 at 07:43:22 PT
By Stuart Hutson, The Battalion Texas A&M U.
Source: U-WIRE
John has just spent the last five years of his life in college studying and has now been hired for his dream job, but first, he must pass one more exam -- a drug test. As he drops his pants to deliver a urine sample, John's mind swims back to a party one week ago where his friends were partaking of an illegal, post-graduation joint. While he did not participate in the weed smoking, he wonders if the second-hand pot smoke will be enough to send him to the unemployment line. 
These are common questions asked by those faced with undergoing a drug test. How precise are drug testing techniques, and what happens after someone fills one of those little cups? Dr. Jack Zaun, the chief of laboratory operations for One Source Toxicology Laboratories in Deer Park, Texas, said the laboratory technicians begin a drug evaluation by sending the sample through an immunological or "screening" test to determine whether any drugs are present in the sample. "Your standard urine test is set up to test for five basic drugs: cocaine, heroin, codeine or morphine, amphetamines, and PCP," Zaun said. "But no drug test is just limited to those. Anything that is carried in any fluid within the human body can be tested." Zaun said the drugs selected for screening are determined by the job or situation of the testing. Those being tested under suspicion for illegal drug use by law enforcement may be tested for a gambit of drugs ranging from PCP to Ecstasy. Those being tested for a job fueling airplanes may be tested primarily for nicotine. During this screening, a cocktail of organic chemicals is mixed with part of the sample. For each drug that is being looked for, there is a reagent, or antibody, that will react with the particular drug for which it is designed. "All drugs are organic in nature -- they have to be in order to interact with the organic human body," Zaun said. "As such, there are antibodies that will single each drug out and attack it, just like an antibody in the body would attack a particular bacteria." The attack may result in chemical reactions that can be determined by microscopic or spectroscopic examination. The time frame of drug detection measured by the screening process is determined by the kind of sample being examined. For instance, standard urine testing typically will reveal drugs used within the last two or three days. Blood testing normally will reveal drugs used only within the last two or three hours because of the constant filtering of the blood by the body's waste system. "Blood testing for drugs is typically used during postmortem work to see if drugs were a factor in the death," Zaun said. "In this case, the drug is still in the blood, and the blood is much easier to access than urine." Hair testing will reveal a general history of drug use from one week to two months prior to the test. "Hair grows at about one centimeter a month, so we can't test for anything used one week prior to the test," Zaun said. If any drugs are detected during this screening process, the sample is analyzed for the amount of the drug present. "There are specific levels of each drug in the sample that we typically look for in order to rule out the possibility of passive inhalation (such as in John's case) or an exposure that may have happened a long time ago," Zaun said. "For instance, we typically look for 50 nanograms (50 parts per billion) when examining for marijuana. But, with the equipment any lab has, they can look for as little as one part per billion. If you have ever been exposed to pot in the last few months, it would show up (at one part per billion) because marijuana will deposit itself in the body's fat cells and stay there." A common tactic of those wishing to elude a positive result on a drug test is to dilute their urine with water. "A real dilute sample always sends up a red flag during testing," Safe said. "Most testing facilities will immediately request a second sample be taken as soon as possible so that we can tell what is really going on." The amount of a drug in a sample is determined by separating the drug from the rest of the sample and then measuring that amount with a mass spectrometer. "Each drug is dissolved into whatever the sample is composed of, so we change the conditions of the sample until the particular drug can't stay dissolved," Zaun said. The method can be compared to the components of salad dressing settling to the bottom of the jar when the dressing is cooled in a refrigerator. For most samples, the acidity is altered until the particular drug settles out and collects onto an organic plate. That plate is analyzed by a mass spectrometer, which sends a beam of light through the plate and then measures the light leaving the plate to determine it's composition. "This methodology is 99.99999 percent effective," Zaun said. "On the rare event that any mistake happens, it is almost always a clerical error that can be easily fixed." Posted: July 6, 2000(U-WIRE) College Station, Texas(C) 2000 The Battalion via U-WIRE  Copyright  2000 At Home CorporationCannabisNews Drug Testing Archives:
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Comment #2 posted by W MARTIN on June 19, 2001 at 12:56:32 PT:
cheating a urinalysis
is there an effective way to pass a urinalysis? does niacin work, or drinking gallons of water, I am looking at 30 days in a military brig I I fail this upcoming whiz quiz so if you know any tricks that don't require me to add something to the sample (I will be watched well) please email me about it.                Sincerely,                  W. A. Martin
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Comment #1 posted by observer on July 06, 2000 at 11:47:46 PT
You're In
seeBusiness Alchemist Turns Urine Into Gold Entrepreneurs
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