Detection urine adulteration and their parameters to be tested
Introduction:
Urine drug testing plays an important role in monitoring licit and illicit drug use for both medico-legal and clinical purposes. One of the major challenges of urine drug testing is adulteration, a practice involving manipulation of a urine specimen with chemical adulterants to produce a false negative test result urine. The use of urine adulterants can cause false negative results in drug tests by either interfering with the screening test and/or destroying the drugs present in the urine.
PARAMETERS TESTED:
Creatinine is a waste product of creatine; an amino acid contained in muscle tissue and found in urine. A person may attempt to foil a drug test by drinking excessive amounts of water or diuretics such as herbal teas to "flush" the system. Creatinine and specific gravity are two ways to check for dilution and flushing, which are the most common mechanisms used in an attempt to circumvent drug testing. Low creatinine and specific gravity levels may indicate diluted urine. The absence of creatinine (<5mg/dl) is indicative of a specimen not consistent with human urine.
Specific gravity tests for sample dilution. The normal range for specific gravity is from 1.003 to 1.030. Values outside this range generally indicate specimen dilution or adulteration.
Nitrite tests for commonly used commercial adulterants such as "Klear" or "Whizzies". They work by oxidizing the major cannabinoid (marijuana) metabolite THC COOH�. Normal urine should contain no trace of nitrites. Positive results generally indicate the presence of an adulterant
Glutaraldehyde tests for the presence of an aldehyde. Adulterants such as "UrinAid" and "Clear Choice" contain glutaraldehyde which may cause false negative screening results by disrupting the enzyme used in some immunoassay tests. Glutaraldehyde is not normally found in human urine; therefore, detection of glutaraldehyde in a urine specimen is generally an indicator of presence of adulteration.
pH tests for the presence of acidic or alkaline adulterants in urine. Normal pH levels should be in the range of 4.0 to 9.0. Values outside of this range may indicate the sample has been altered.
Oxidants/PCC (Pyridinium Chlorochromate) tests for the presence of oxidizing agents such as bleach and hydrogen peroxide. Pyridinium chlorochromate (sold under the brand name "UrineLuck") is a commonly used adulterant. Normal human urine should not contain oxidants or PCC.
TEST PROCEDURE:-
urine adulteration test is based on the color derived from the chemical reaction between the chemical reagent on each test pad and the urine sample. A color chart(shown above) indicating abnormal and normal test result color values for each of the six parameters tested is printed on the test container. One test strip is dipped in the urine sample for 1-2 seconds immersing all reagent test pads. The strip is then blotted on its side to remove excess sample. After one (1) minute the colors of the six reagent pads are visually compared to the color chart and results obtained for each of the six test parameters. An abnormal result for any of the six parameters suggests the sample has been manipulated, altered or otherwise contaminated and a new sample should be obtained for further testing.
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