The importance of Verifying Urine Samples


By: Kumar W. Giri

May 21, 2016


We have all heard the stories of how offenders tamper with their own urine samples.  Diluted samples have become a common instance, usually by the time the sample has been checked by a lab it is too late.  What choice are the courts and probation left with?  Most of the time the option is to either violate the offender for dilution or just ignore the test and wait until the next time they test to see what happens.


The first step to making sure that samples are not tampered with is security and visually monitoring the client when the sample is being taken.  This first step not only helps with the prevention of urination devices but also helps stop the use of synthetic urine which is very difficult to detect via testing.


The second step to make sure samples are not tampered with is to test for adulterants.  The adulterant strips should be used at the time of collection, it is important to verify the sample before performing any type of test or sending it out to a lab.   There are multiple brands of adulterant strips on the market, most test for a minimum of 7 common adulterants.  The following guide lists the adulterants and the effects on the drug testing process.


Creatinine:  This is a byproduct of Creatine which is used by the body to make muscle.  Creatinine has two primary uses in urine analysis  The first is help check for dilution, a low level of Creatinine is the first indication that the sample may be diluted.  Creatinine can also be used as an indicator of new marijuana, creatinine will stay in the system for a longer time than THC.  An example of how the ratios work are below:


Specimen A B C
Collection Date: 08-02-11 08-10-11 08-20-11
THC level (ng/ml): 350 450 180
Creatinine level (mg/dl) 52 150 20
THC/CR Ratio : 6.7 3.0 9.0


Specimen A has a THC/CR ratio of 6.7 compared to Specimen B with a ratio of 3.0. Over this time period, the decline is consistent with abstinence.  However, new marijuana use is indicated in the time period between Specimen B and Specimen C.  Although the THC levels decreased the lowered creatinine level can help indicate there was some type of new use because the THC/CR ratio increased from 3.0 to 9.0. (Norchem 1999)


Glutaraldehyde: Glutaraldehyde has also been used as an adulterant to alter urine drug test results.  This product is available under the trade name UrinAid. The manufacturer sells this product for $20 to $30 per kit. Each kit contains 4 to 5 mL of glutaraldehyde solution, which is added to 50 to 60 mL of urine.  Glutaraldehyde solutions are available in hospitals and clinics as a cleaning or sterilizing agent.  A 10% solution of glutaraldehyde is available from pharmacies as over-the-counter medication for treatment of warts.  Glutaraldehyde at a concentration of 0.75% by volume can lead to false-negative screening results for a cannabinoid test using the EMIT II drugs-of-abuse screen.  Amphetamine, methadone, benzodiazepine, opiate, and cocaine metabolite tests can be affected at glutaraldehyde concentrations between 1% and 2% with EMIT immunoassays.  At a concentration of 2% by volume, the assay of cocaine metabolites is significantly affected (apparent loss of 90% sensitivity).  A loss of 80% sensitivity was also observed with the benzodiazepine assay.  (Medscape 2007)


Nitrite:  This tests for common adulterants like Klear or Whizzies.  These adulterants work by oxidizing the marijuana metabolite THC-COOH.  Normal urine should contain no trace of nitrite.  If the urine is nitrite positive, then the urine was probably adulterated.


Oxidants:  This tests for the presence of oxidizing agents such as bleach and hydrogen peroxide.  UrineLuck, a popular adulterant product, is one of the agents tested for.  Normal human urine should not contain oxidants or PCC.


pH-Testing:  This tests for the presence of acidic or alkaline adulterants in urine.  Normal pH levels should be between 4.0 and 9.0. If outside this range, the sample may have been altered.


Specific Gravity: This tests for sample dilution.  The normal range is between 1.003 to 1.030.  If the value is not within this range it may be the result of dilution or adulteration.  This detects if the client has flooded their system with water right before a test to dilute the results of the test.


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.


At MDADS, we prescreen all samples for adulterants before any type of test or process for lab verification has been started.  This helps insure the most accurate and dependable test results for the courts and clients.  For more information about our testing procedures please visit or email us at


Norchem. (1999, February 15). THE CREATININE LEVEL. In Norchem Lab. Retrieved May 17, 2016, from

Dasgupta, A. (2007). The Effects of Adulterants and Selected Ingested Compounds on Drugs-of-Abuse Testing in Urine. Am J Clin Pathol128(3), 491-503. Retrieved May 17, 2016.

How To Catch Someone Trying To Pass A Drug Test. (n.d.). In Home Health Testing. Retrieved May 17, 2016, from

Cheat Protection Chart. (n.d.). In Employee Drug Testing Ace. Retrieved June 17, 2016, from