Introduction Drug testing in urine has long been performed in the pre-employment or “for cause” seting. With the explosion of the opioid epidemic, urine drug testing has expanded into areas such as substance- abuse treatment, pain management, and drug courts. Te consequences of unexpected positives may be severe; this may include everything from denial of employment to incarceration. To avoid the consequences of an undesired result, various strategies may be employed by the drug user, including adulteration, substitution, and dilution of urine1
.
Synthetic urine may be used to substitute for the patient’s real urine. It may be purchased from vendors, who sell it in lyophilized form to be reconstituted, or as a liquid. Normally, laboratories offer specimen-validity testing, which includes creatinine, pH, and a test of oxidants2
. Te
synthetic urine is not only drug-free, but made so as to not be detected as abnormal with these tests. Currently, validity testing may be performed via a “dipstick” or “quick test” method, or with liquid reagent on an autoanalyzer. In the dipstick method, a solid reagent is immersed in the sample, which causes a color change on the device that indicates a result. Tis method allows for a specimen collector to determine the validity of a sample quickly and to assign further testing as needed. Te liquid reagent method is performed in the laboratory, not at collection, but allows the validity determination to be made quickly across hundreds or even thousands of samples without subjective operator interpretation. Tese two approaches are described for detecting synthetic urine.
Method Tirty-one samples were taken from donors and set aside for testing using a standard adulteration panel on an Olympus AU- 600. Of these samples, nine were known synthetic urines substituted by donors,
www.datia.org
ten were normal urines that were free from drugs of abuse, ten were normal urines that were positive for a drug of abuse, one was a known mix of real human and synthetic urines, and one was a synthetic urine developed for calibration (zero calibrator). Aliquoted into each Hitachi aliquot cup were 2mL of each sample; these were then randomly placed into a sampling rack for an Olympus AU-600. Te initial test consisted of eight of the known synthetics, along with the zero calibrator and a normal, negative, human urine. Te sample set was then tested five times concurrently. Aſter the initial testing, the remaining samples of negative and non-negative human urines were added to the previous sample set to test for the accuracy of the reagent and dipstick. Te samples were then tested four times over a period of two days. All of the samples were tested via dipstick method and were re-aliquoted in new Hitachi cups before being tested on the Olympus. Te dipstick was then placed aside and visually examined aſter approximately one minute had elapsed. Te resulting colorimetric change was then logged to later compare with the liquid reagent. Te samples were then tested and compared, not only with the dipstick test previously performed, but also against a synthetic database that the team had collated from numerous synthetic urines. Of note is that while the standard adulteration assay tests for common effects of adulterants (adjustments to chromate values, aldehyde values, oxidant values, etc.), the focus of this research is on the synthetic test values only.
Results Te results of the test indicate that the reagent and strip are able to correctly detect the presence of synthetic urine against a known, real sample. Te real urine had a significant colorimetric response on the dipstick, while the synthetic urine had litle to no response aſter a period of 60 seconds. Tis indicates that a collector using the
strip would be able to more correctly ascertain the validity of the sample on a rapid test. Te figures on page 32 show the
synthetic values returned by the Olympus autoanalyzer. Figure A.1 shows the results of the initial testing performed by the team. Nine known synthetics were run in a random order against a known, real human urine to test synthetic values for the liquid reagent. Te results showed that the reagent returned values around -100 for the synthetic urines, while the real human urine sample returned a value in the mid-400 range. Tis test was repeated four additional times to test the effectiveness over time. As the graph shows, the reagent was able to continue providing the same results. Figure A.2 shows the results of the multi-day test for the liquid reagent. Te graph indicates that the regent was able to return negative values for the synthetics and showed random positive values for the human urines. Te known human urines that returned negative results were sent for further biological testing and were confirmed to either have had infections or were very dilute samples. Of note is that every synthetic tested, as well as the mixed urine, was correctly identified as having synthetic components. Te figure also has several data points that were truncated that had positive values well over 1,000. Figure A.3 shows the qualitative results of the dipstick test. Te table shows the number of samples that passed or failed for the method’s given test. Te dipstick relies on a visible color change on the stick to indicate the presence of real human urine. A result of no color change or a bright red color indicates that the sample is either a synthetic sample or has been adulterated in some way. Te liquid reagent shows a value that is either a positive or negative number. A resulting negative number is considered a fail, meaning that the sample is pulled for
datia focus 31
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52
