Investigation of adulteration methods for drug abuse analysis and urine integrity tests

It's known that cases admitted to illicit drug analysis laboratory to attempt to adulteration methods to hide substance use or to obtain negative results. Tampering with specimen can be dilution, substitution or adulteration. Illicit drug screening results were evaluated in 5709 cases who have admitted to our laboratory in 2015. Cases that have creatinine values of the <20 mg/dl were normalized. In addition, the ways followed by the person who attempted to substitution and records were examined. A urine pool was prepared with 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (Δ9-THC-COOH), amphetamines (AMP) and 3,4-methylenedioxy-methamphetamine (MDMA) above the legal limits. Household adulteration agents such as bleach, vinegar, drain opener and the eye drops were added in varying amounts into the urine specimen taken from this pool. All specimens were examined in terms of physical characteristics, urine integrity tests and with two different card tests and immunoassay. 2.15% (n=123) of the cases have <20 mg/dL creatinine value and 11 cases were determined to be diluted. 10 cases have been detected give substituted urine in during the sample collection step. Δ9-THC-COOH level was given false negative results with immunoassay in the urine involved bleach (10% v/v). It was observed MDMA level was given negative result with increasing volume of vinegar. Addition drain opener caused an error in the tests, while eye drops did not cause any change. The study results were revealed that the importance of chain of custody, pre-analytical, analytical and post-analytical steps should be undertaken together in the illicit drug analysis laboratories. Urine integrity tests should be performed for each urine sample reaching the laboratory. Due to the different creatinine values in community, by calculating the value of creatinine in the laboratory, which is each community of the area where the laboratory, is required normalization.