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Published:
Journal of Analytical Toxicology,
ISSN 0146-4760,
Volume 24,
Number 6, September 2000, pp. 456
Here is where the title stuff goes
Letter to the Editor—Evaluation of Intect™ Test Strips for Detecting
Adulteration of Urine Specimens Used For Drugs-of-Abuse Testing
Edward J. King
East Side Physicians, PLLC, 55 East 86th Street, New York, New York
10128
To the Editor:
Common problems in drugs-of-abuse testing are the use of commercial
adulterants, dilution of the specimen with water, or the addition of common
household products in an attempt to cause false-negative results in screening
and confirmation tests (1). Intect 6 test strips from Branan (Santa Ana, CA)
were evaluated for their ability to visually detect various common adulterants
in urine. Two tests, creatinine and specific gravity (SG), are intended to detect
exogenous dilution of urine. Four other tests detect chemical interferants.
These are nitrite, glutaraldehyde, pH, and bleach (sodium hypochlorite).
Urine samples from healthy volunteers were collected and assayed for creatinine
on the Hitachi 911 Auto-analyzer (Roche, Indianapolis, IN). Values ranged from
100 to 225 mg/dL of creatinine. When these urines were assayed with Intect 6
there was little or no reaction noted on the creatinine test pads. Occasional
violet mottling was noted on some of the pads. The five other tests performed
adequately when dipped into urines from healthy volunteers. Other than creatinine,
no false-positive adulterations were noted for these tests.
Ten urines were diluted to less than 10 mg/dL of creatinine. The values were
confirmed on the Hitachi 911. These were found to test positive for exogenous
dilution by the Intect 6 creatinine and SG test strips. The creatinine results
were most likely artifacts of the pad’s inability to react (2).
Intect 6 strips were able to detect the presence of nitrites when the commercial
adulterants Klear and Urine-Luck were added to normal urine samples. Specimens
spiked with glutaraldehyde were identified by Intect 6 strips (3).
Intect 6 pads reacted to the presence of bleach in adulterated urines. However,
the pH pad remained at 5-6 even after the addition of 10 mL of bleach to a 50-mL
urine specimen. Drano™, which contains potassium hydroxide and sodium hypochlorite,
was added to 50-mL samples of urine. The Intect 6 pH test pad showed that a
strong base had been added, indicating adulteration. The bleach pad showed no
reaction to the presence of Drano. Although only 2 mL of Drano was added, the
SG pad gave a positive result for dilution.
The use of this product for the detection of adulteration of drugs-of-abuse
samples cannot be recommended. The creatinine assay will show that all specimens
have been diluted, and the erratic nature of some of the other tests may lead
to interpretation problems at the point of collection.
References
1. S.L. Mikkelson and K.O. Ash. Adulterants causing false negatives
in illicit drug testing. Clin. Chem. 34: 2333–2336 (1988).
2. S.B. Needleman, M. Porvaznik, and D. Ander. Creatinine analysis in
single collection urine specimens. J. Forensic Sci. 37: 1125–1133
(1992).
3. S. George and R.A. Braithwaite. The effect of glutaraldehyde adulteration
of urine specimens on Syva Emit II drugs-of-abuse assays. J. Anal.
Toxicol. 20: 195–196 (1996). Reproduction
of editorial content of this journal is prohibited without publisher’s
permission.
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