Evaluation of Common Adulterants in Morphine Urine Drug Screening

Abstract

Background: Manipulating drug screens, changing sample quality, and confounding test results are common practices seen among opium users. These practices are intended to deceive drug screening systems using a wide variety of commonly available chemical compounds such as lemon juice and fertilizer. These actions create a challenge for addiction screening reference labora- tories. Objectives: Therefore, we studied the eects of lemon juice, nitrogen-based chemical fertilizers, carbon copy paper, and urine sam- ple dilution on morphine urine screening test results. PatientsandMethods: We studied the urine samples of all individuals who were referred to the drug laboratory at Sabzevar public health center from August 2014 to August 2015. Out of 8012 urine samples tested in one year, morphine metabolites were identified in 493 (6%) of the urine samples using a rapid morphine slide test and thin-layer chromatography. Next, 180 confirmed positive samples were randomly assigned to three groups of 60 samples each, to which were added either carbon paper, lemon juice, or nitrogen-based fertilizer. Results: The test results showed that in the carbon paper and lemon juice groups, 59 samples tested positive for morphine, and one sample was distorted. In the fertilizer group, 57 samples were positive and 3 were distorted. None of the groups showed negative test results. Moreover, negative results were not seen when testing standard samples that had been adulterated in the test kit's sensitivity range and higher. However, fertilizer and lemon juice adulteration, but not carbon paper, can lead to false negative results with lower morphine concentrations (150 ng/mL). Conclusions: We found that adding nitrogen-based fertilizer, lemon juice, or carbon copy paper to urine samples does not facilitate false negative results when using a rapid slide morphine urine test. However, testing samples of various standard concentrations of morphine showed that at lower morphine concentrations, adding lemon juice or fertilizer can aect the test results.