marijuana

Illicit drug abuse remains a serious public wellness issue. According to the 2013 National Survey on Drug Abuse and Health, an estimated 24.6 million Americans age 12 years and older were current illicit drug users—ix.4% of the U.Southward. population. Marijuana was the most commonly abused illicit drug, followed past cocaine, heroin, and hallucinogens.

Federal guidelines define an adulterated specimen equally a urine specimen containing either a substance that is non a normal constituent or an endogenous substance at a concentration that is not a normal physiological concentration. Pre-employment screening programs typically do not involve direct supervision of specimen collection, so employment candidates may endeavor to cheat drug testing by adulterating specimens. This makes it essential for laboratories to identify pre-analytically any such adulterated specimens.

Ways of Cheating a Drug Examination

Commonly people try to cheat drug testing by three different ways: substituting their urine with constructed urine or drug-gratuitous urine purchased from a clandestine source; drinking a commercially available production to flush out drugs; or adding an adulterant in vitro to the urine specimen after collection.

Synthetic urine is difficult to observe because it has like pH, creatinine, and specific gravity to normal urine. Specific tests are needed to place compounds that are normal constituents of man urine but not found in synthetic urine, such as cortisol. Commercially available products that adulterate urine or flush out drugs can be classified nether two broad categories. The first includes fluids or tablets that, along with drinking large amounts of water, dilute urine. Common products are Absolute Detox XXL drink, Accented Carbo Drinks, Set up Clean Drug Detox Drink, Fast Flush Capsules, and Fix Make clean Gel Capsules.

The second category of products is in vitro urinary adulterants that are added to urine after collection. Examples include Stealth (peroxidase and peroxide), Klear (nitrite), Clean Add-It-ive (glutaraldehyde) and Urine Luck (pyridinium chlorochromate [PCC]). In improver, iodine is a potent oxidizing agent and may potentially destroy abused drugs, specially marijuana metabolites (2). Enquiry besides indicates that papain with intrinsic ester hydrolysis ability could significantly reduce the concentration of 11-nor-9-carboxy-ix-tetrahydrocannabinol (THC-COOH), a metabolite of marijuana, if added to the urine specimen in vitro (3).

Household Chemicals every bit Urinary Adulterants

Would-be drug examination cheaters might try adulterating their specimens with household chemicals, but nearly tin can be detected by specimen integrity testing. Both collection sites and laboratories accept at their disposal a number of mechanisms to detect potentially invalid specimens. The temperature, for instance, should be within ninety.5–98.9°F. The specific gravity should be between 1.005–one.030, and pH should exist between 4.0–x.0. The creatinine concentration should be 20–400 mg/dL. However, some drug testing laboratories consider a creatinine concentration of 15 mg/dL as the lower end cutoff. Ane common adulterant, sodium chloride, always produces a specific gravity greater than 1.035 if added at a concentration necessary to produce a false-negative outcome.

Unfortunately, specimen integrity testing doesn't detect all adulterants. For example, it won't pick up adulteration of urine with Visine center drops, isopropanol, or other urinary adulterants. Withal, constructive spot tests and special urine dipsticks are available (See Table one).

Flushing, Detoxification Agents, and Diuretics

Flushing and detoxification agents are oft advertised as effective ways of passing drug tests. Many of these products contain caffeine or other diuretics to increase the output of urine, as well as saccharide 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. evaluated the issue of backlog fluid ingestion on imitation-negative marijuana and cocaine urine test results by studying the ability of Naturally Clean Herbal Tea, goldenseal root, and hydrochlorothiazide to cause simulated negative results. Volunteers drank one gallon of h2o, herbal tea, or took hydrochlorothiazide 22 hours after smoking marijuana cigarettes or intranasal administration of cocaine. Their creatinine levels dropped beneath the cutoff two hours later intake of excessive fluid. Marijuana and cocaine metabolite levels (as measured by both enzyme multiplied immunoassay technique [EMIT] and fluorescence polarization immunoassay [FPIA]) decreased significantly and ofttimes switched from positive to negative in subjects later on consuming ii quarts of fluid. Fifty-fifty backlog h2o was effective in diluting a urine specimen to cause imitation negative results, although herbal tea diluted urine faster compared to water lonely (v).

Using Spot Tests

When specimen integrity testing cannot find an adulterated specimen, laboratories can apply a variety of effective spot tests.

• Urine Luck Wu et al. reported that the active ingredient of "Urine Luck" was PCC, a stiff oxidizing agent, which at a concentration of 100 gm/L, acquired significantly decreased response rate for all EMIT Two drug screens, indicating the possibility of false-negative results. In contrast, for the Abbott Abuscreen exam, only morphine and marijuana assays were affected, but a false-positive result was observed with the amphetamine assays. This cariosity of urine did not alter GC/MS confirmation of methamphetamine, benzoylecgonine, and phencyclidine, but apparent concentrations of opiates and THC-COOH were significantly reduced. Wu et al. also described a unproblematic spot test using 1,v-diphenylcarbazide in methanol (10 gm/L) to detect the presence of PCC in urine, in which a reddish regal colour developed in the presence of PCC (6). Moreover, adding a few drops of 3% household hydrogen peroxide solution to approximately 0.5 mL of urine specimen caused firsthand development of a night dark-brown color and nighttime chocolate-brown precipitate if PCC was nowadays in the urine. As a strong oxidizing agent, PCC could besides liberate iodine from potassium iodide solution in acidic medium (7). Notably, several other adulterants available online contain PCC.

• Nitrite Containing Agents Products such equally "Klear," which contains potassium nitrite, can cause interference in GC/MS confirmation of THC-COOH. Notwithstanding, 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. However, concentrations of nitrite unremarkably are below 36 µg/mL in such specimens, while nitrite concentrations are one,910–12,200 µg/mL in urine specimens adulterated with nitrite (9). Nitrite can exist easily detected by elementary spot tests. Improver of a few drops of a nitrite-adulterated urine specimen to 0.v mL of one% potassium permanganate solution, followed by improver of a few drops of 2N hydrochloric acid, turned the pink permanganate solution colorless with effervescence. Another spot test to detect nitrite used 1% potassium iodide solution. Adding a few drops of nitrite adulterated urine to 0.5 mL of potassium iodide solution, followed past addition of a few drops of 2N muriatic acid, resulted in firsthand release of iodine from the colorless potassium iodide solution. If whatsoever organic solvent, such equally hexane, was added the iodine was readily transferred in the organic layer giving the layer a distinct color of iodine (7). Nitrite could besides be detected by diazotizing sulfanilamide and coupling the product with Northward-(1-napthyl) ethylenediamine.

 • Stealth Stealth is an adulterant which consists of two vials, one containing a powder (peroxidase) and another vial containing a liquid (hydrogen peroxide), both added to the urine. Stealth is capable of invalidating immunoassay screening of THC-COOH, LSD, and opiates using both Roche ONLINE assays and Microgenics CEDIA assays if these drug or metabolites are nowadays in modest concentrations (125–150% of cutoff values). In addition, GC/MS confirmation could be affected (ten). Valtier and Cody described a rapid spot test to detect the presence of Stealth in urine. Add-on of 10 µL of urine to l µL of tetramethylbenzidine working solution, followed by improver of 500 µL of 0.1 M phosphate buffer solution acquired the specimen to turn dark brownish. Peroxidase activity could besides be monitored by using a spectrophotometer (xi). 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 colour developed immediately, which usually faded with fourth dimension.

• Glutaraldehyde Glutaraldehyde containing products were one of the first that appeared in the marketplace to invalidate drugs of abuse testing. Glutaraldehyde solutions are also bachelor in hospitals and clinics as a cleaning agent. Glutaraldehyde at a concentration of 0.75% volume could lead to false-negative screening results for a cannabinoid examination using the EMIT II drugs of abuse screen. Amphetamine, methadone, benzodiazepine, opiate, and cocaine metabolite tests are also affected at glutaraldehyde concentration between 1 and ii% using EMIT II immunoassays. Wu et al. described a simple fluorometric method for the detection of glutaraldehyde in urine. When 0.5 mL of urine was heated with 1.0 mL of 7.7 mmol/L potassium dihydrogen phosphate (pH 3.0) saturated with diethyl-thiobarbituric acid for 1 hr at 96–98°C in a heating cake, a yellow green fluorophore developed if glutaraldehyde was present. Shaking the specimen with north-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 besides be estimated using a fluorometer (14).

• Zinc Sulfate: A New Urinary Adulterant Although not widely used, zinc sulfate is an effective urinary adulterant that could invalidate all drug tests using EMIT analysis. Currently there is no suitable method for detecting zinc sulfate in adulterated urine. Therefore, 2 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 one mL of urine containing zinc sulfate resulted in formation of a white precipitate, which was soluble in backlog sodium hydroxide. In the second spot test, addition of 3–4 drops of 1% sodium chromate solution to 1 mL of urine containing zinc sulfate followed past improver of four–v drops of 1N sodium hydroxide led to formation of a yellowish precipitate (zinc chromate) (15).

Testing Urine Specimens for Adulterants

Specially designed urine dipsticks such as AdultaCheck four, AdultaCheck 6, or Intect seven can be used to notice many adulterants in urine. AdultaCheck 6 detects creatinine, oxidants, nitrite, glutaraldehyde, pH, and chromate. The Intect vii test strip for checking adulteration in urine is equanimous of seven different pads to examination for creatinine, nitrite, glutaraldehyde, pH, specific gravity, bleach, and PCC.

Guidelines from the Substance Corruption and Mental Health Services Administration crave additional tests for urine specimens with abnormal concrete characteristics or ones that show characteristics of an adulterated specimen during initial screening or confirmatory tests. A pH less than 3 or more than 11, and nitrite concentrations greater than 500 mg/mL point the presence of adulterants. A nitrite colorimetric test or a general oxidant colorimetric test should be performed to identify nitrite.

The presence of chromium (VI) in a urine specimen likewise is indicative of adulteration at a cutoff concentration of 50 mg/mL. The presence of chromium in a urine specimen could exist 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 exist used as adulterants. The presence of these halogens should exist 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 assimilation spectrophotometer, capillary electrophoresis, or inductively coupled plasma mass spectrometry.

To detect glutaraldehyde, laboratories should use a general aldehyde test or the feature immunoassay response in ane or more drug immunoassay tests for initial screening. Similarly, the presence of PCC should be confirmed using a general examination for the presence of oxidant and a GC/MS confirmatory test. Finally, surfactant should be verified by using a surfactant colorimetric test with a greater than or equal to 100 mg/mL dodecyl benzene sulfonate equivalent cutoff.

Conclusion

It is essential for laboratories to notice adulterated urine in the pre-analytical step, as many adulterants invalidate immunoassay screening tests. Although routine specimen integrity tests tin can detect most of the household adulterants except Visine eye drops and booze/isopropanol, adulterants containing strong oxidizing agents such every bit potassium nitrite, pyridinium chlorochromate, or Stealth require a different arroyo. Spot tests, peculiarly designed urine dipsticks, as well as more analytically sophisticated methods such every bit chromatographic methods, are available in the toxicology laboratory to identify these adulterants. If a urine specimen is adulterated it must be documented and reported, simply no further testing is necessary.

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Amitava Dasgupta, PhD, DABCC, FACB, is a professor of pathology and laboratory medicine at the University of Texas-Houston Medical School. He is the medical manager of laboratory services of TIRR-Memorial Infirmary as well as director of clinical chemistry and point-of-intendance testing at Memorial-Hermann Hospital in Houston. He has published 209 peer-reviewed papers in various journals and is on the editorial board of v journals.
 +Email: [email protected]