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Pre-employment screening programs typically do not involve direct supervision of specimen collection, so employment candidates may attempt to cheat drug testing by adulterating specimens. This makes it essential for laboratories to identify pre-analytically any such adulterated specimens. Usually people try to cheat drug testing by three different ways: substituting their urine with synthetic urine or drug-free urine purchased from a clandestine source; drinking a commercially available product to flush out drugs; or adding an adulterant in vitro to the urine specimen after collection.
Synthetic urine is difficult to detect because it has similar pH, creatinine, and specific gravity to normal urine. Specific tests are needed to identify compounds that are normal constituents of human urine but not found in synthetic urine, such as cortisol. Commercially available products that adulterate urine or flush out drugs can be classified under two broad.
The first includes fluids or tablets that, along with drinking large amounts of water, dilute urine. The second category of products is in vitro urinary adulterants that are added to urine after collection. In addition, iodine is a strong oxidizing agent and may potentially destroy abused drugs, especially marijuana metabolites 2. Would-be drug test cheaters might try adulterating their specimens with household chemicals, but most can be detected by specimen integrity testing.
Both collection sites and laboratories have at their disposal a of mechanisms to detect potentially invalid specimens. The temperature, for instance, should be within The specific gravity should be between 1. One common adulterant, sodium chloride, always produces a specific gravity greater than 1.
However, effective spot tests and special urine dipsticks are available See Table 1. Flushing and detoxification agents are frequently advertised as effective means of passing drug tests. Many of these products contain caffeine or other diuretics to increase the output of urine, as well as sugar and natural or artificial flavoring agents. The objective is to produce diluted urine so that concentrations of abused drugs and or metabolites fall below the recommended cutoff concentrations. Cone et al.
Volunteers drank one gallon of water, herbal tea, or took hydrochlorothiazide 22 hours after smoking marijuana cigarettes or intranasal administration of cocaine. Their creatinine levels dropped below the cutoff 2 hours after intake of excessive fluid. Marijuana and cocaine metabolite levels as measured by both enzyme multiplied immunoassay technique [EMIT] and fluorescence polarization immunoassay [FPIA] decreased ificantly and frequently switched from positive to negative in subjects after consuming 2 quarts of fluid. Even excess water was effective in diluting a urine specimen to cause false negativealthough herbal tea diluted urine faster compared to water alone 5.
When specimen integrity testing cannot detect an adulterated specimen, laboratories can employ a variety of effective spot tests. In contrast, for the Abbott Abuscreen test, only morphine and marijuana assays were affected, but a false-positive result was observed with the amphetamine assays. Wu et al. As a strong oxidizing agent, PCC could also liberate iodine from potassium iodide solution in acidic medium 7. Notably, several other adulterants available online contain PCC. However, a bisulfite step at the beginning of sample preparation can eliminate this problem 8.
Nitrite in urine may arise in vivo in patients receiving medications such as nitroglycerin, isosorbide dinitrate, and nitroprusside, or due to urinary tract infection. Nitrite can be easily detected by simple spot tests. Addition of a few drops of a nitrite-adulterated urine specimen to 0. Adding a few drops of nitrite adulterated urine to 0. If any How many water pills to pass a drug test solvent, such as hexane, was added the iodine was readily transferred in the organic layer giving the layer a distinct color of iodine 7.
Nitrite could also be detected by diazotizing sulfanilamide and coupling the product with N- 1-napthyl ethylenediamine. Valtier and Cody described a rapid spot test to detect the presence of Stealth in urine. Peroxidase activity could also be monitored by using a spectrophotometer Our investigation showed that if a few drops of a urine specimen adulterated with Stealth were added to potassium dichromate followed by a few drops of 2N hydrochloric acid, a deep blue color developed immediately, which usually faded with time. Glutaraldehyde solutions are also available in hospitals and clinics as a cleaning agent.
Glutaraldehyde at a concentration of 0. When 0. Shaking the specimen with n-butanol resulted in the transfer of this adduct to the organic layer which could be viewed under long wavelength UV light. Glutaraldehyde in urine can also be estimated using a fluorometer Currently there is no suitable method for detecting zinc sulfate in adulterated urine. Therefore, two rapid spot tests to detect the presence of zinc sulfate in urine were developed.
Addition of 3—4 drops of 1N sodium hydroxide solution to approximately 1 mL of urine containing zinc sulfate resulted in formation of a white precipitate, which was soluble in excess sodium hydroxide. Specially deed urine dipsticks such as AdultaCheck 4, AdultaCheck 6, or Intect 7 can be used to detect many adulterants in urine. AdultaCheck 6 detects creatinine, oxidants, nitrite, glutaraldehyde, pH, and chromate.
The Intect 7 test strip for checking adulteration in urine is composed of seven different p to test for creatinine, nitrite, glutaraldehyde, pH, specific gravity, bleach, and PCC. Guidelines from the Substance Abuse and Mental Health Services Administration require additional tests for urine specimens with abnormal physical characteristics or ones that show characteristics of an adulterated specimen during initial screening or confirmatory tests.
A nitrite colorimetric test or a general oxidant colorimetric test should be performed to identify nitrite. The presence of chromium in a urine specimen could be confirmed by a chromium colorimetric test or a general test for the presence of oxidant.
A confirmatory test should be performed using multi-wavelength spectrophotometry, ion chromatography, atomic absorption spectrophotometry, capillary electrophoresis, or inductively coupled plasma mass spectrometry. Elemental halogens, such as pure bromine or iodine, can also be used as adulterants. The presence of these halogens should be confirmed by a halogen colorimetric test or a general test for the presence of oxidants. Confirmatory tests may employ multi-wavelength spectrophotometry, ion chromatography, atomic absorption spectrophotometer, capillary electrophoresis, or inductively coupled plasma mass spectrometry.
To detect glutaraldehyde, laboratories should use a general aldehyde test or the characteristic immunoassay response in one or more drug immunoassay tests for initial screening. It is essential for laboratories to detect adulterated urine in the pre-analytical step, as many adulterants invalidate immunoassay screening tests. Spot tests, specially deed urine dipsticks, as well as more analytically sophisticated methods such as chromatographic methods, are available in the toxicology laboratory to identify these adulterants.
If a urine specimen is adulterated it must be documented and reported, but no further testing is necessary. Pidd K, Roche AM. How effective is drug testing as a workplace safety strategy? A systematic review of the evidence. Accid Anal Prev ;— Paul B, Jacobs A. Spectrophotometric detection of iodide and chromic III in urine after oxidation to iodine and chromate. J Anal Toxicol ;— Papain: A novel urine adulterant. Toxicological screening for drugs of abuse in samples adulterated with household chemicals.
S Afr Med J ;—9. In vivo adulteration: Excess fluid ingestion cause false negative marijuana and cocaine urine test. Adulteration of urine by Urine Luck. Clin Chem ;—7. Rapid spot tests for detecting the presence of adulterants in urine specimens submitted for drug testing. Am J Clin Pathol ;—9. J Anal Toxicol ;—2. Nitrite adulteration of workplace drug testing specimens: Sources and associated concentrations of nitrite and distinction between natural sources and adulteration.
Analysis of morphine and codeine in samples adulterated with Stealth. J Anal Toxicol ;—5. Valtier S, Cody JT.How many water pills to pass a drug test
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OBJECTIVE TESTING – URINE AND OTHER DRUG TESTS