Update on Urine Adulterants and Synthetic Urine Samples to Subvert Urine Drug Testing.

To avoid a positive urine drug test, donors might try to subvert the test, either by adulterating the specimen with a product designed to interfere with testing or by substituting the specimen for a synthetic urine. A market search conducted in December of 2020 identified 3 adulterants and 32 synthetic urines, and a selection was procured based on specific criteria. Samples prepared with the 3 adulterants and 10 synthetic urines were submitted for testing at five forensic drug testing laboratories to perform immunoassay screening, chromatographic confirmation analysis and specimen validity testing (SVT). One adulterant determined to contain iodate reduced THC-COOH concentrations by 65% and the concentrations of 6-acetylmorphine, morphine, oxycodone, oxymorphone, hydrocodone and hydromorphone by 6-27%. Another adulterant determined to contain nitrite reduced THC-COOH concentrations by 22%, while the third did not affect drug screening or confirmatory testing. Both active adulterants could be identified through positive oxidant screens as well as through signal suppression in cloned enzyme donor immunoassay (CEDIA). The synthetic urines could not be identified either through traditional SVT or by the AdultaCheck10 dipstick. The Synthetic UrineCheck dipstick produced a difference in response between the authentic urine specimen and the synthetic urine samples, but the difference was small and difficult to observe. While most synthetic urines now contain uric acid, magnesium and caffeine, the results indicated that a biomarker panel including endogenous and exogenous markers of authentic urine performed well and clearly demonstrated the absence of biomarkers in the synthetic urines. The SVT assay also offers potential targets for future screening assays.